Ankylosing Spoondylitis and Disability Evaluation

[Quality of life of patients with ankylosing spondylitis]
Sierakowska M, Karpinska A, Sierakowski S, Krajewska-Kulak E, Kamienska I, Domyslawska I, Karpińska A, Krajewska-Kułak E, Kamieńska I, Domysławska I.
Ann Acad Med Stetin. 2006;52 Suppl 2:29-37.
[Article in Polish]
Zakład Pielegniarstwa Ogólnego, Wydział Pielegniarstwa i Ochrony Zdrowia Akademii Medycznej w Białymstoku ul. Kilińskiego 1, 15-089 Białystok.
Ankylosing spondylitis is ranked second among "great rheumatic diseases" which lead to considerable disability. The course of ankylosing spondylitis is chronic with variations in intensity of symptoms and is either continuously progressive or alternates with exacerbations and remissions. Difficulties in everyday life are due to limited motoric activity which makes full self-functioning rather impossible. The specificity of ankylosing spondylitis negatively affects the emotional state of patients. Patients are depressed, apathetic, discouraged to undertake treatment and rehabilitation. The aim of the present study was to assess the quality of life of patients with ankylosing spondylitis in four dimensions: physical, psychic, environmental and social; to determine the severity of anxiety and depression associated with the disease; and to analyze the quality of life and health. Diagnostic questionnaires were used in this study. Our study has shown that patients are unsatisfied with the quality of their health. In the course of the disease, physical and psychic symptoms exacerbate. Support and help are especially needed by persons living alone and by residents of villages. It seems that professional care, psychic support, education of the patient and of persons caring for him, and preparation to self-care are an integral part of therapy which may have an important effect in improving the quality of life.

The influence of illness and variables associated with functional limitations in Chinese patients with ankylosing spondylitis.
Tam LS, Chan KY, Li EK.
J Rheumatol. 2007 May;34(5):1032-9. Epub 2007 Mar 1 2007 Mar 01.
Department of Medicine and Therapeutics, Prince of Wales Hospital, Chinese University of Hong Kong and Hong Kong Society for Rehabilitation, Hong Kong. lstam@cuhk.edu.hk
OBJECTIVE: To assess the effect of illness and the functional outcome of Chinese patients with ankylosing spondylitis (AS), and to identify variables associated with a poor functional outcome. METHODS: A cross-sectional study was performed in 314 patients with AS who participated in a postal survey on the effects of illness on work capacity, functional limitations, and explanatory variables. Functional limitations were assessed using the Bath AS Functional Index (BASFI). Explanatory variables included sociodemographic characteristics and clinical features. Linear regression analyses were performed to identify variables associated with functional impairment. RESULTS: The mean +/- standard deviation (SD) age of the patients was 44 +/- 11 years, with a mean disease duration of 19 +/- 11 years. The median BASFI was 3 (IQR 1.0-5.3). Twenty-three percent reported AS-related work disability after a median of 11 (IQR 2-17) years. Multivariate analysis identified low family income, education level, disease duration, Bath AS Disease Activity Index (BASDAI) score, and patient's global score as factors associated with functional impairment. In the subgroup of patients with disease duration <> or = 20 years, less education, longer disease duration, and history of peripheral joint pain were associated with functional impairment. BASDAI was associated with functional impairment in both subgroups. CONCLUSION: AS in Chinese patients had significant social and economic impact. Poor socioeconomic background, long disease duration, and high disease activity level were associated with functional impairment.

[Expert assessment topic--disability evaluation of intervertebral disk diseases of the lumbar spine]
Kramer J, Krämer J.
Z Orthop Ihre Grenzgeb. 2006 Nov-Dec;144(6):552-7.
[Article in German]

Identification of the most common problems by patients with ankylosing spondylitis using the international classification of functioning, disability and health.
van Echteld I, Cieza A, Boonen A, Stucki G, Zochling J, Braun J, van der Heijde D.
J Rheumatol. 2006 Dec;33(12):2475-83. Epub 2006 Oct 15.
Department of Physical Medicine and Rehabilitation, Ludwig-Maximilians-University, Munich, Germany.
OBJECTIVE: The International Classification of Functioning, Disability and Health (ICF) aims to classify functioning and health by a number of categories divided over 3 components: body functions and body structures, participation and activities, and environmental factors. We identified the common health problems of patients with ankylosing spondylitis (AS) based on the ICF from the perspective of the patient. METHODS: During structured interviews with the extended ICF checklist, trained assessors collected data from 111 patients with AS. ICF categories identified by more than 5% of the patients as at least mildly impaired or restricted were selected. Categories identified by less than 5% were removed. Additional impairments/restrictions reported by more than 5% of the patients, after the structured interviews and not yet included in the checklist, were added. RESULTS: One hundred nineteen (72%) out of 165 categories of the extended ICF checklist were identified to be at least mildly impaired or restricted. Within each of the 4 components of the ICF, at least one-third of the categories were impaired or restricted for more than 50% of the patients. Thirty-nine (33%) categories were related to movement and mobility. Within the component "environmental factors" the categories "support of immediate family" and "health professionals" were the most important facilitators, "climate" was the most important barrier. Eight impairments were additionally mentioned as relevant. These were hierarchically lower levels of ICF categories previously included and they were added. CONCLUSION: One hundred twenty-seven ICF categories represent the comprehensive classification of functioning in AS from the patients' perspective. The results underscore the need to address the 4 ICF components when classifying functioning and to emphasize that functioning implies more than physical functioning.

Risk factors for functional limitations in patients with long-standing ankylosing spondylitis.
Ward MM, Weisman MH, Davis JC Jr, Reveille JD.
Arthritis Rheum. 2005 Oct 15;53(5):710-7.
National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, US Department of Health and Human Services, Bethesda, MD 20892, USA. wardm1@mail.nih.gov
OBJECTIVE: To identify risk factors for functional limitations in patients with ankylosing spondylitis (AS) of at least 20 years' duration. METHODS: Patients with AS for > or =20 years were enrolled in the cross-sectional component of the Prospective Study of Outcomes in AS. All patients had clinical evaluations and completed questionnaires on functional limitations and potential risk factors. Functional limitations were assessed using the Bath Ankylosing Spondylitis Functional Index (BASFI; score range 0-100, higher scores indicate more limitations) and the Health Assessment Questionnaire for the Spondylarthropathies (HAQS). Risk factors included demographic characteristics, duration of AS, smoking status, number of comorbid medical conditions, recalled level of recreational activity in teens and twenties, occupational physical activity throughout life (rated 1 = little, 2 = moderate, 3 = heavy, and weighted by the number of years in each job), and history of AS in a first-degree relative. RESULTS: The 326 patients (74% men) had a mean +/- SD age of 55.0 +/- 10.7 years, a mean duration of AS symptoms of 31.7 +/- 10.2 years, and a mean BASFI score of 40.7 +/- 25.6. BASFI scores increased with higher lifetime occupational physical activity (r = 0.31; P < r =" 0.25;" r =" 0.12;" p =" 0.04)." p =" 0.0002)," p =" 0.02).">/=20 years are greater among those with a history of more physically demanding jobs, more comorbid conditions, and among smokers, and are less severe among those with higher levels of education and a family history of AS.

Neck pain is a major clinical problem in ankylosing spondylitis, and impacts on driving and safety.
Holden W, Taylor S, Stevens H, Wordsworth P, Bowness P.
Scand J Rheumatol. 2005 Mar-Apr;34(2):159-60.

Reliability of the Canadian Occupational Performance Measure in patients with ankylosing spondylitis.
Kjeken I, Dagfinrud H, Uhlig T, Mowinckel P, Kvien TK, Finset A.
J Rheumatol. 2005 Aug;32(8):1503-9.
National Resource Center for Rehabilitation in Rheumatology and Department of Rheumatology, Diakonhjemmet Hospital, Norway. ingvild.kjeken@nrrk.no
OBJECTIVE: The Canadian Occupational Performance Measure (COPM) is a client-centered measure, designed to detect changes in occupational performance over time. The main aim of our study was to examine the test-retest reliability of the Norwegian version of the COPM in patients with ankylosing spondylitis (AS) in 3 different retest modes of data collection. METHODS: A total of 119 patients with AS completed the baseline COPM interview before randomization into one of 3 modes of retest data collection performed 2 weeks later: by personal interview, telephone interview, or mailed questionnaire. Scores were computed for Performance and Satisfaction, and the 2 sets of scores were examined for reliability by intraclass correlations (ICC), and by the Bland-Altman procedure for calculation of smallest detectable difference (SDD). RESULTS: The ICC coefficients for Performance and Satisfaction were as follows: 0.92 and 0.93 (rescoring by personal interview), 0.73 and 0.73 (rescoring by telephone interview), and 0.90 and 0.90 (rescoring by mail). SDD for the Performance and Satisfaction scores were 1.47 and 1.80, respectively, for rescoring by personal interview; 3.14 and 4.00 for rescoring by telephone interview; and 2.20 and 2.41 for rescoring by mailed survey. CONCLUSION: The results confirm that the COPM is a reliable instrument for use in clinical practice in patients with AS, and may serve as an instrument to promote a patient-centered approach in the planning and evaluation of rehabilitation programs. Mailed questionnaires may replace personal interview in followup examinations, while rescoring by telephone interview is less reliable.

Early disease course and predictors of disability in juvenile rheumatoid arthritis and juvenile spondyloarthropathy: a 3 year prospective study.
Selvaag AM, Lien G, Sorskaar D, Vinje O, Forre O, Flato B, Sørskaar D, Førre Ø, Flatø B.
J Rheumatol. 2005 Jun;32(6):1122-30.
Department of Rheumatology, Rikshospitalet University Hospital, Oslo, Norway. anne.marit.selvaag@rikshospitalet.no
OBJECTIVE:. To describe the 3 year disease course in early juvenile rheumatoid arthritis (JRA) and juvenile spondyloarthropathy (JSpA), to compare the health status after 3 years of followup with that of normal controls, and to investigate the relationship between physical function at followup and disease characteristics recorded during the first 6 months. METHODS: One hundred and ninety-seven children (median age 6:6 yrs) with JRA and JSpA and disease duration <1.5 style="font-weight: bold;">Validity and reliability of an Italian version of the revised Leeds disability questionnaire for patients with ankylosing spondylitis.
Lubrano E, Sarzi Puttini P, Parsons WJ, D'Angelo S, Cimmino MA, Serino F, Pappone N.
Rheumatology (Oxford). 2005 May;44(5):666-9. Epub 2005 Mar 9 2005 Mar 09.
Fondazione Maugeri, IRCCS, Istituto Telese Terme, Rheumatology and Rehabilitation Research Unit, Telese Terme (BN), Campania, Italy. enniolubrano@hotmail.com
OBJECTIVE: The purpose of the present study was to produce an Italian version of the Revised Leeds Disability Questionnaire (LDQ) in a group of patients with ankylosing spondylitis, and to examine the psychometric properties of this version, evaluating its internal consistency, external validity and reliability. METHODS: The LDQ was administered to 60 Caucasian patients affected by ankylosing spondylitis (50 males, 10 females, mean age 46.1 +/- 14.2 yr, range 22-74, median disease duration 4.5 yr, range 1-24) together with the Italian version of the Stanford Health Assessment Questionnaire (HAQ), and anthropometric measurements. Thirty patients completed the questionnaire after a 10-day interval. Internal consistency was evaluated with Cronbach's alpha coefficient of reliability. Construct validity of the LDQ was evaluated using the correlation between the HAQ and anthropometric measurements. Test-retest reliability was assessed with the intraclass correlation coefficient. RESULTS: All patients completed the validation study. The questionnaire was internally consistent (alpha=0.90). A significant correlation was recorded between the LDQ and the HAQ score (rho=0.841, P<0.01) correlation="0.97)." style="font-weight: bold;">Impact of functional impairment in ankylosing spondylitis: impairment, activity limitation, and participation restrictions.
Dagfinrud H, Kjeken I, Mowinckel P, Hagen KB, Kvien TK.
J Rheumatol. 2005 Mar;32(3):516-23.
Section for Health Science, University of Oslo, PO Box 1153, Blindern, 0316 Oslo, Norway. h.s.dagfinrud@medisin.uio.no
OBJECTIVE: To describe difficulties in everyday activities related to impaired function in patients with ankylosing spondylitis (AS), and to examine possible sex differences in the impact of the disease. In addition, to examine the relationships between measures of personal characteristics, impairment, and activity/participation levels within the framework of the International Classification of Functioning (ICF). METHODS: A total of 152 patients with AS took part in a clinical examination including anthropometric measures, blood samples, and self-reported disease related measures. The Canadian Occupational Performance Measure (COPM) interviews were performed to describe and measure activity limitations and participation restrictions perceived by the patient during the last year. The study variables were categorized and analyzed according to the levels of the ICF model using bivariate and multivariate statistical approaches. RESULTS: The mean age of patients was 47 (SD 13) years, 58% were men, and the mean disease duration was 15 (SD 12) years. The problems most frequently reported in COPM interviews were "interrupted sleeping," "turn head when driving," "carry groceries," and ""having energy for social activities." Women reported higher level of disease activity and more physical limitations than men. Disease activity and reduced mobility (impairment variables) seemed to result in more activity/participation restrictions in female than in male patients. The impairment variables explained only one-third of the activity and participation restrictions perceived by patients. CONCLUSION: Activity limitations and participation restrictions reported by patients were only partly explained by the impairment variables. Further research should identify social, structural, and attitudinal barriers influencing activity and participation in patients with AS.

Evaluation of the Turkish version of the Dougados functional index in ankylosing spondylitis.
Ozer HT, Sarpel T, Gulek B, Alparslan ZN, Erken E.
Rheumatol Int. 2005 Jun;25(5):368-72. Epub 2005 Mar 2 2005 Mar 02.
Department of Rheumatology-Immunology, Faculty of Medicine, Cukurova University, Balcali 01330, Adana, Turkey. teozer@cu.edu.tr
To investigate the reliability and validity of the Turkish version of the Dougados functional index (DFI) in patients with ankylosing spondylitis (AS). The Turkish version of DFI was obtained after a translation and back-translation process. Seventy consecutive patients with AS were enrolled. Patients were requested to complete the questionnaire on the day of admission (first visit), a second time within 24 h after admission (second visit), and on a third occasion. Reliability, validity and reproducibility of the Turkish version of the index were assessed. All the items showed significant correlations with the total index score with r-values ranging from 0.516 to 0.817. Cronbach alpha score was calculated as 0.908. Significant correlations were found between the total DFI score and Schober test (r=-0.293, P<0.05), r="0.384;" r="0.450," r="-0.331," r="0.352," r="between" style="font-weight: bold;">The Turkish version of the Bath Ankylosing Spondylitis Functional Index: reliability and validity.
Ozer HT, Sarpel T, Gulek B, Alparslan ZN, Erken E.
Clin Rheumatol. 2005 Apr;24(2):123-8. Epub 2004 Aug 31.
Department of Rheumatology-Immunology, Faculty of Medicine, Cukurova University, 01330 Adana, Turkey. teozer@cu.edu.tr
The purpose of this study was to investigate the reliability and validity of the Turkish version of the Bath Ankylosing Spondylitis (AS) Functional Index (BASFI). The Turkish version of the BASFI was obtained after a process of translation and back-translation. Eighty-one consecutive patients meeting the 1984 New York criteria for AS were enrolled. Patients were evaluated and requested to complete the questionnaire at days 1 and 2 and on a third occasion between days 15-90. Reliability, reproducibility, validity and sensitivity to change of the Turkish version of the index were assessed. Each score correlated closely with the index score, with coefficients between 0.727 and 0.844. Reliability analysis showed a Cronbach's alpha score of 0.926. Correlations were found between all items of the BASFI and Schober's test (r=-0.258 to -0.531, p<0.001-0.05), r="0.284" r="0.334" r="0.515," r="-0.444," r="0.567," r="0.535," r="-0.403," r="0.371," r="0.765-0.917," style="font-weight: bold;">Functional disability and quality of life in patients with ankylosing spondylitis.
McKenna SP, Doward L.
Rheumatol Int. 2004 Jan;24(1):57-8; author reply 59-60. Epub 2003 Oct 24.
Comment on:
Rheumatol Int. 2003 May;23(3):121-6.

Factors associated with body function and disability in patients with ankylosing spondylitis: a cross-sectional study.
Falkenbach A, Franke A, van der Linden S.
J Rheumatol. 2003 Oct;30(10):2186-92.
Gasteiner Heilstollen Hospital, A-5645 Bad Gastein, Austria. falke@gasteiner-heilstollen.com
OBJECTIVE: To determine for patients with ankylosing spondylitis (AS) which factors are associated with disability and restricted body function. METHODS: In 1538 patients with AS, occiput-to-wall distance, chest expansion, cervical rotation, finger-floor distance, and modified Schober test were measured cross-sectionally, and for each measure the patient's respective percentile was calculated. The mean of the 5 percentiles was summarized in the mobility restriction score (MRS). In addition, patients answered questions on disease progression and completed the Bath AS Functional Index (BASFI) questionnaire. All data were coded into 40 variables, used as independent variables in multiple regression analyses to identify factors associated with BASFI and MRS. RESULTS: Finger-to-floor distance (beta positive, +), cervical rotation (-), time since first AS symptoms (-), age (+), height loss (+), maximum height (-), delay in diagnosis (+), hip replacement (+), regular practice of sports (-), chest expansion (-), sex (worse BASFI in females), exposure to cold and dampness (+), and regular participation in AS group physical exercises (+) were significantly associated with worse BASFI. Significantly associated factors for worse MRS were height loss (+), sex (higher MRS in males), active inflammation of the cervical region (+), age (+), maximum height (-), active inflammation of the hip region (+), involvement of shoulders (+), time since first AS symptoms (+), urethritis (-), regular practice of sports (-), involvement of feet (-), and hip replacement (+). The models explain 47% of the variance observed for both the BASFI and MRS. CONCLUSION: The amount of variance explained for both BASFI and MRS is rather high. The results apply primarily to groups of patients, but are insufficient to guide clinical decisions in individual patients. These findings contribute to our understanding of factors influencing disability and restriction in body function in AS.

Functional disability and quality of life in patients with ankylosing spondylitis.
Bostan EE, Borman P, Bodur H, Barca N, Barça N.
Rheumatol Int. 2003 May;23(3):121-6. Epub 2002 Oct 30.
Comment in:
Rheumatol Int. 2004 Jan;24(1):57-8; author reply 59-60. PMID: 14576961.
Clinic of Physical Medicine and Rehabilitation, Numune Education and Research Hospital, Samanpazari, 06100 Ankara, Turkey.
The aim of this study was to evaluate functional disability and quality of life (QOL) in patients with ankylosing spondylitis (AS) and determine the relationship between functional status and measures of clinical condition including QOL. Fifty-one AS patients (45 male, six female) with a mean age of 37.2+/-10.8 years were included. The demographic data of the patients were recorded. Their clinical status was assessed using the Bath Ankylosing Spondylitis Metrology Index (BASMI), Bath Ankylosing Spondylitis Radiology Index (BASRI), and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Global pain of the patients was determined with a visual analog scale (VAS), and QOL status was evaluated with the Nottingham Health Profile (NHP). Twenty-seven patients (52.9%) had peripheral articular involvement. Sixty percent had mild-to-moderate and 25.4% of the patients had severe functional disability, while 5.8% did not report any functional loss. A significant change in the mean scores of all clinical measures except BASRI was observed between patients with and without peripheral arthritis. The clinical measures of disease (BASRI, BASMI, and BASDAI) were all correlated with each other and with laboratory variables. The strongest factors correlating with functional loss were BASMI and BASDAI. The scores of all sections of the NHP were significantly higher, indicating a poor quality of life in AS patients. Peripheral joint involvement had a significant role in the deterioration of QOL. Physical domains of NHP such as pain and physical activity had highest correlations with functional disability, whereas psychosocial domains of NHP were found to correlate more highly with BASDAI and VAS pain scores. These results show the effect of AS, especially when the disease is active and associated with peripheral involvement. In conclusion, current management strategies should focus on decreasing pain, maintaining physical activity, and efforts to improve psychosocial health aspects for increasing QOL in patients suffering from AS.

Assessment of disability with the World Health Organisation Disability Assessment Schedule II in patients with ankylosing spondylitis.
van Tubergen A, Landewe R, Heuft-Dorenbosch L, Spoorenberg A, van der Heijde D, van der Tempel H, van der Linden S, Landewé R.
Ann Rheum Dis. 2003 Feb;62(2):140-5.
Department of Internal Medicine, Division of Rheumatology, University Hospital Maastricht, Maastricht, The Netherlands.
OBJECTIVE: To investigate in ankylosing spondylitis (AS) whether the newly developed World Health Organisation Disability Assessment Schedule II (WHODAS II) is a useful instrument for measuring disability, to assess its responsiveness in relation to other traditional disease specific instruments, and to identify factors that are associated with both short term and long term scores on the WHODAS II. METHODS: Patients with AS from a randomised controlled trial assessing the efficacy of spa treatment (n=117) and from a five year longitudinal observational study (n=97) participated. The patients completed several questionnaires, including the WHODAS II. After a three week course of spa treatment, 31 patients again completed all questionnaires to assess responsiveness. To determine to what degree the WHODAS II reflects some AS oriented measures on disease activity, functioning, and quality of life, correlation coefficients between the WHODAS II and these other questionnaires were calculated. Responsiveness was calculated by the effect size (ES) and standardised response mean (SRM). Linear regression analysis was performed to explore which factors might be associated with short term changes on the WHODAS II and to investigate (in the observational study) which factors of WHODAS II might predict disability five years later. RESULTS: Mean score on the WHODAS II was 23.9 (SD 15.5 (range 0.0-76.1)). Scores on the WHODAS II were significantly correlated with all disease specific questionnaires measured (all p<0.001). p="0.007)." p="0.002)" style="font-weight: bold;">[Expert assessment of patients with seronegative spondyloarthropathies]
Kellner H.
Z Rheumatol. 2002 Dec;61(6):643-51.
[Article in German]
Rheuma-Einheit, Medizinische Poliklinik, Klinikum der Universität München, Innenstadt, Pettenkoferstr. 8a, 80336 München. Kellner@medpoli.med.uni-muenchen.de
Besides rheumatoid arthritis, seronegative spondyloarthropathies are one of the most common inflammatory musculoskeletal diseases. The main clinical manifestations are spondylitis and sacroiliitis, but peripheral arthritis and involvement of other organ systems are known as well. The typical ankylosis of the spine is resulting in a marked loose of the functional capacity. During the course of disease, work disability is progressing and finally the patient may become permanent disabled. Patients with ankylosing spondylitis can be viewed by experts for several reasons. To guarantee an objective medical expert view, a detailed clinical examination and use of clinical indices are mandatory.

Measuring disability in ankylosing spondylitis: comparison of bath ankylosing spondylitis functional index with revised Leeds Disability Questionnaire.
Eyres S, Tennant A, Kay L, Waxman R, Helliwell PS.
J Rheumatol. 2002 May;29(5):979-86.
Comment in:
J Rheumatol. 2002 May;29(5):865-8. PMID: 12022341.
Rheumatology and Rehabilitation Research Unit, University of Leeds, England, UK.
OBJECTIVE: Disability has been identified as a core outcome measure in ankylosing spondylitis (AS). The Dougados Functional Index (DFI) and the Bath Ankylosing Spondylitis Functional Index (BASFI) have been selected as core measures of function in this disease. However, neither of these instruments has undergone rigorous psychometric testing. METHODS: The psychometric properties of 2 measures of disability, the BASFI and the revised Leeds Disability Questionnaire (RLDQ), were compared in a cohort of 208 outpatients with AS. Rasch analysis was used to examine the properties of each measure and to compare them on a common scale. Test-retest was assessed in a cohort of 149 subjects who completed each instrument twice over an interval of 2 weeks. RESULTS: Both instruments gave an even spread of scores across the study group, but BASFI responses were positively skewed and RLDQ responses negatively skewed. There was a highly significant difference between perceived severity groups for both instruments (Kruskal-Wallis chi-squared: RLDQ, 75.1; BASFI, 80.4; both p < icc =" 0.95," icc =" 0.94," style="font-weight: bold;">Functional disability predicts total costs in patients with ankylosing spondylitis.
Ward MM.
Arthritis Rheum. 2002 Jan;46(1):223-31.
Veterans Affairs Palo Alto Health Care System, CA 94304, USA. mward@leland.stanford.edu
OBJECTIVE: To describe the composition and distribution of total costs of ankylosing spondylitis (AS), and to identify predictors of high total costs among patients with AS. METHODS: In a prospective longitudinal study, 241 patients with AS reported information on health status, health care utilization, treatments, and work limitations on biannually mailed questionnaires. Annual direct costs were estimated on the basis of reported ambulatory care visits, hospitalizations, diagnostic tests, medications, assistive devices, nonallopathic treatments, travel to visits, and paid household help. Indirect costs were estimated from the number of work days missed or, for retirees and homemakers, the number of days of activity limitation. A similar analysis was performed for cumulative costs over 5 years in a subset of 111 patients. RESULTS: Annual total costs averaged $6,720 (in 1999 US dollars; median $1,495). Indirect costs comprised 73.6% and direct costs comprised 26.4% of total costs, although only 95 patients (39%) contributed to the indirect costs. Functional disability was the most important predictor of high total costs. The likelihood of having high (>$10,000) total costs increased by a factor of 3 with each 1-point increase in the Health Assessment Questionnaire disability index modified for the spondylarthropathies (HAQ-S; range 0-3). Results were similar in the subgroup of 111 patients who were followed up for 5 years, among whom the likelihood of high cumulative total costs (>$50,000 over 5 years) increased by >6 times with each 1-point increase in the HAQ-S. CONCLUSION: Functional disability is the most important predictor of total costs in patients with AS. Interventions that maintain or improve patients' functional ability will likely have the greatest potential to decrease the costs of AS.

Work disability among people with ankylosing spondylitis.
Barlow JH, Wright CC, Williams B, Keat A.
Arthritis Rheum. 2001 Oct;45(5):424-9.
Psychosocial Research Centre: Chronic Conditions & Disability, School of Health & Social Sciences, Coventry University, UK. jbarlow@coventry.ac.uk
OBJECTIVE: To investigate work disability among people with ankylosing spondylitis (AS) in terms of correlates and coping mechanisms. METHODS: The sample group (n = 133) was recruited through 2 sources: 1) consecutive patients attending outpatient clinics over a 6-month period, and 2) a random sample of members of the National Ankylosing Spondylitis Society. We used a cross-sectional survey with data collected by self-administered questionnaires and telephone interviews with a randomly selected subsample (n = 6). RESULTS: The majority of participants were men. The mean age was 49 years; the mean disease duration was 28 years. Thirty-one percent were unable to work because of AS, with an additional 15% reporting changes to their working lives attributable to AS (e.g., reduction in hours worked, change of job). Compared with being in full-time work, work disability was associated with being older, longer disease duration, lower educational standard, comorbidity, greater physical impairment, pain, fatigue, stiffness, anxious and depressed mood, and lower self-esteem. Descriptive data added further insight into the experience of work disability and coping with AS in a work environment. CONCLUSION: Work disability is worthy of further investigation to determine exact prevalence rates and psychosocial implications. Work disability could be addressed with simple interventions or adaptations in the workplace.

Employment, work disability, and work days lost in patients with ankylosing spondylitis: a cross sectional study of Dutch patients.
Boonen A, Chorus A, Miedema H, van der Heijde D, van der Tempel H, van der Linden S.
Ann Rheum Dis. 2001 Apr;60(4):353-8.
Department of Rheumatology, University Hospital Maastricht, PO Box 5800, 6202 AZ Maastricht, The Netherlands. aboo@SINT.AZM.NL
OBJECTIVE: To evaluate employment status, work disability, and work days lost in patients with ankylosing spondylitis (AS). METHODS: A questionnaire was sent to 709 patients with AS aged 16-60. The results of 658 of the patients could be analysed. RESULTS: After adjustment for age, labour force participation was decreased by 15.4% in male patients and 5.2% in female patients compared with the general Dutch population. Work disability (all causes) was 15.7% and 16.9% higher than expected in the general population for male and female patients respectively. In particular, the proportion of those with a partial work disability pension was increased. Patients with a paid job lost 5.0% of work days as the result of having AS, accounting for a mean of 10.1 days of sick leave due to AS per patient per year in addition to the national average of 12.3 unspecified days of sick leave. CONCLUSION: This study on work status in AS provides data adjusted for age and sex, and the differences from the reference population were significant. The impact of AS on employment and work disability is considerable. Work status in patients with AS needs more attention as an outcome measure in future research.

Risk factors for work disability in patients with ankylosing spondylitis.
Ward MM, Kuzis S.
J Rheumatol. 2001 Feb;28(2):315-21.
Medical Service, VA Palo Alto Health Care System, California 94304, USA.
OBJECTIVE: To identify risk factors for work disability in patients with ankylosing spondylitis (AS). METHODS: Risk factors for permanent work disability and for receipt of disability payments were assessed using Cox regression models in a retrospective cohort study of 234 patients with AS. Candidate risk factors included age at onset of AS, sex, race, education level, marital status, the presence of comorbid conditions, smoking and drinking history, recreational activity, occupation, and physical activity at work. Risk factors for changes in the type of work performed, decrease in number of hours worked, long sick leave, and the need for help at work were assessed using logistic regression models in a prospective study of the subset of 144 patients who reported working for pay during the study. Candidate risk factors for these aspects of work disability were age, sex, race, education level, levels of functional disability, pain and stiffness, changes in functional disability, pain or stiffness over the preceding 6 months, minutes/week of recreational exercise, back exercises, freedom of movement at work, control over the pace of work, and physical activity at work. RESULTS: In a cohort of 234 patients with a median duration of AS of 21.4 years, 31 patients (13.2%) developed permanent work disability and 57 patients (24.3%) had received disability payments. Older age at onset of AS, less formal education, and having had jobs that were more physically active were significant risk factors for permanent work disability. These factors, along with the presence of a comorbid condition and being female, were also significantly associated with the receipt of disability payments. In a prospective study of 144 patients followed for a median of 4 years, higher levels of functional disability and pain were associated with increased risks of decreased work hours, long sick leaves, and needing help at work, while higher levels of pain were also associated with an increased risk of changing the type of work performed. Women were significantly more likely than men to change their type of work or decrease their work hours. Patients whose jobs were more physically demanding were more likely to change their type of work or need help at work. CONCLUSION: Patients with AS who have physically demanding jobs are more likely to experience permanent or temporary work disability, or need to change the type of work done or receive help at work, than those with jobs that are less physically demanding.

Reliability and validity of a Swedish version of the Revised Leeds Disability Questionnaire for patients with ankylosing spondylitis.
Stenström CH, Hellström S, Hultgren M, Wikström M.
Scand J Rheumatol. 2000;29(4):243-8.
Department of Physical Therapy, Karolinska institutet, Huddinge, Sweden.
The aim of the study was to investigate the reliability and the validity of a Swedish version of the Revised Leeds Disability Questionnaire (RLDQ). Forty-two patients, 36 men and 6 women, median age 52.5 years, median symptom duration 24 years, with spondylarthropathy were assessed with the RLDQ, three questions on the content of the questionnaire, and range-of-motion measures. The results indicated satisfactory test-retest stability and internal consistency, and only minor internal redundancy. RLDQ items were generally considered relevant and suggested additions were similar to items already included in the questionnaire. Patients with low disability scores tended to be older and have better joint mobility than those with higher scores. Physiotherapists observed and scored disability significantly higher than patients. Correlations between subscores of the RLDQ and range-of-motion measures were in the main weak. In conclusion the Swedish version of the RLDQ may be considered as reliable and valid.

A new dimension to outcome: application of the Bath Ankylosing Spondylitis Radiology Index.
Calin A, Mackay K, Santos H, Brophy S.
J Rheumatol. 1999 Apr;26(4):988-92.
Epidemiology Department, Royal National Hospital for Rheumatic Diseases, Bath, UK. mpssb@bath.ac.uk
Our aim was to develop a reproducible and simple radiological scoring system for ankylosing spondylitis (AS) to use in cross sectional and prospective studies. Regarding validation of the BASRI (Bath Ankylosing Spondylitis Radiology Index), radiographs of 470 patients with AS were scored using the New York criteria for the sacroiliac joints. The lumbar and cervical spine, and hips were similarly graded 0-4. These scores were added together to give BASRI-t (total) and if the hips are excluded to give BASRI-s (spine). Radiographs of 188 patients were used to test reproducibility. Blinded radiographs of 89 non-AS patients were included randomly to assess disease specificity. Sensitivity to change was assessed using 177 radiographs from 40 patients. Regarding the cross sectional study, 2200 radiographs of 550 (104 F:446 M) patients were randomly selected and scored using BASRI. The frequency distribution of BASRI-t and BASRI-s were plotted using a probit plot. Inter and intraobservation showed between 73 and 82% and 73 and 88% complete agreement, with specificity of 0.78-0.89, suggesting scores are disease-specific. Sensitivity to change became apparent at 2 years (p<0.05). r="0.293," style="font-weight: bold;">A comparative study of the usefulness of the Bath Ankylosing Spondylitis Functional Index and the Dougados Functional Index in the assessment of ankylosing spondylitis.
Spoorenberg A, van der Heijde D, de Klerk E, Dougados M, de Vlam K, Mielants H, van der Tempel H, van der Linden S.
J Rheumatol. 1999 Apr;26(4):961-5.
Department of Internal Medicine, University Hospital Maastricht, The Netherlands. jspo@sint.azm.nl
To determine whether the Bath Ankylosing Spondylitis Functional Index (BASFI, score 0-10) or Dougados Functional Index (DFI, score 0-40) is superior in measuring physical function in ankylosing spondylitis (AS) we studied 191 consecutive outpatients with AS in the Netherlands, France, and Belgium. The participating centers are secondary and tertiary referral centers. The external criterion for disease activity (DA) was: both patient and physician assessment of disease activity on a visual analog scale (VAS) and the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). The external criterion for damage was 2 radiological scores of the spine; BASRI-s (Bath Ankylosing Spondylitis Radiology Index-spine) and a modified SASSS (Stoke Ankylosing Spondylitis Spine Score). Median scores for BASFI and DFI were 2.5 (range 0-10) and 8.5 (range 0-35), respectively. Spearman correlation coefficient between both indexes was 0.89. The average correlation with disease activity variables was 0.42 for BASFI and 0.41 for DFI. For both BASFI and DFI the correlation with BASRI-s was 0.42 and with SASSS 0.36. When distinguishing between patients with high and low disease activity, sensitivity for both indexes was between 76 and 94%, while specificity was between 66 and 87% for all 3 DA measures. Average misclassification between BASFI, DFI and DA was 23 and 27%, respectively. Both BASFI and DFI correlate equally well with disease activity and damage.

Comparison of the Dougados Functional Index and the Bath Ankylosing Spondylitis Functional Index. A literature review.
Ruof J, Stucki G.
J Rheumatol. 1999 Apr;26(4):955-60.
Rheumaklinik und Institut für Physikalische Medizin, Zurich, Switzerland.
The preliminary core set for endpoints in ankylosing spondylitis (AS) clinical trials includes physical function. The objective of this review was to compare properties and performance of the 2 most widely used measures of functional capacity in AS: the Dougados Functional Index (DFI) and the Bath Ankylosing Spondylitis Functional Index (BASFI). A MEDLINE search was performed covering the years 1988 through April 1998. AS studies were identified and selected if they included the DFI and/or the BASFI. Additional studies were identified by scrutinizing the references cited in the retrieved articles and by correspondence with the authors of the 2 questionnaires. The instruments were examined with respect to development, truth, discrimination, and feasibility. We identified 27 articles dealing with the instruments. Both are valid and reliable measures of functional capacity in AS. While the DFI was sensitive to change in one disease controlling (DC-ART) and in 4 symptom modifying antirheumatic drug (SMARD) clinical trials, the BASFI is not sufficiently tested in these settings. The only direct comparison of both indices in a physical therapy setting confirmed 4 other studies that suggested a better discriminative capacity of the BASFI in physical therapy clinical trials. Two likely reasons for the lack of responsiveness of the DFI in these settings are the distribution of baseline scores showing a tendency towards normal values and the less sensitive scoring system. Discriminative capacity of the BASFI was found to be superior in patients with mild functional disability. It remains to be seen whether the BASFI performs as well as or better than the DFI in SMARD and DC-ART clinical trials.

Validity and sensitivity to change of spondylitis-specific measures of functional disability.
Ward MM, Kuzis S.
J Rheumatol. 1999 Jan;26(1):121-7.
Comment in:
J Rheumatol. 1999 Jan;26(1):4-6. PMID: 9918233.
Medical Service, VA Palo Alto Health Care System, California 94304, USA.
OBJECTIVE: To compare the construct validity and sensitivity to change of 2 spondylitis-specific measures of functional disability, the Health Assessment Questionnaire Disability Index modified for the spondyloarthropathies (HAQ-S) and the Dougados Functional Index, with 2 more generic instruments, the Health Assessment Questionnaire (HAQ) and the Arthritis Impact Measurement Scales-2 (AIMS2), in patients with ankylosing spondylitis (AS). METHODS: Construct validity was assessed in 2 ways: (1) by comparisons of the cross sectional correlations between each functional disability instrument and 6 measures of physical impairment in 216 patients, and (2) by relating changes over time in the HAQ-S and the Functional Index with changes in patient reported pain and stiffness in 153 patients followed for at least 2 years. Sensitivity to change was measured from the responses of 155 patients who reported a qualitative change in the activity of their AS during followup. RESULTS: Most patients had mild functional disability, with median scores of 0.5 on the HAQ-S (possible range 0-3), 0.375 on the HAQ (possible range 0-3), 11 on the Functional Index (possible range 0-40), and 5 on the AIMS2 (possible range 0-60). Scores on the HAQ-S (R2 = 0.24) and the unmodified HAQ (R2 = 0.18) were more highly correlated with measures of physical impairment than were scores on the AIMS2 (R2 = 0.10) or the Functional Index (R2 = 0.09). Changes over time in the HAQ-S and HAQ were more closely related to changes in pain and stiffness than were changes in the Functional Index. The HAQ-S and HAQ were also more sensitive to change than the Functional Index. CONCLUSION: The HAQ-S showed greater construct validity and sensitivity to change than the Functional Index, but performed similarly to the unmodified HAQ.

[Work capacity evaluation in patients with ankylosing spondylitis]
Grazio S, Jajić Z, Nemcić T, Jajić I.
Reumatizam. 1997;45(2):1-5.
[Article in Croatian]
Klinika za fizikalnu medicinu, rehabilitaciju I reumatologiju KB Sestre milosrdnice, Zagreb.
The aim of the study was to establish the employment and working ability for patients with ankylosing spondylitis. The study was performed using a questionnaire mailed to 185 patients with verified diagnosis of ankylosing spondylitis who were treated at the Department of Rheumatology of the University Hospital "Sestre milosrdnice" in Zagreb in the last 5 years. The questionnaire included a few categories of questions and here we analysed those referring the working abilities. The answers were obtained from 92 patients. We took in account the data for 79 patients who fall into the age group of working population (men to 65 yrs, women to 60 yrs.). In that group there were 50 men and 29 women. Twenty-six patients have a full time job, 7 patients have a part-time job, one changed the job and 45 of them are retired. The difference of working abilities was observed regarding to the physical requirement for the job (P < n =" 34),"> 0.05). The results of our study suggest that ankylosing spondylitis reduce the working ability especially for patients who have a hard job. There is an imperative to maintain the working abilities of patients with ankylosing spondylitis as long as possible.

[Socio-professional aspects of ankylosing spondylitis in Switzerland]
Fellmann J, Kissling R, Baumberger H.
Z Rheumatol. 1996 Mar-Apr;55(2):105-13.
[Article in German]
Orthopädische Universitätsklinik Balgrist, Zürich, Schweiz.
In this study, using a questionnaire, data were collected about the disease, the working conditions and problems, the working ability, the unemployment and the invalidity of 1134 patients suffering from ankylosing spondylitis (Bechterew's disease). In 739 cases (65.2%) a statistical evaluation could be made. 62.2% had pain when working; the reasons were most often the long working time, the position at work, and the climatic factors at the workplace. The solutions to working problems were often applied too late or they did not correspond to the needs of the patients with ankylosing spondylitis. Generally the working ability was with 97.3% high and the invalidity with 2.7% low.

Bath Ankylosing Spondylitis Functional Index.
Calin A, Jones SD, Garrett SL, Kennedy LG.
Br J Rheumatol. 1995 Aug;34(8):793-4.
Comment on:
Br J Rheumatol. 1994 Sep;33(9):842-6.

[Surgical treatment of kyphotic spinal deformities in ankylosing spondylitis using the Harrington compression system: long-term results based on the MOPO scales in the framework of a retrospective questionnaire]
Halm H, Metz-Stavenhagen P, Schmitt A, Zielke K.
Z Orthop Ihre Grenzgeb. 1995 Mar-Apr;133(2):141-7.
[Article in German]
Zentrum für Wirbelsäulenchirurgie, Werner-Wicker-Klinik, Bad Wildungen-Reinhardshausen.
INTRODUCTION: Meanwhile a lot of papers have been published concerning the operative treatment of kyphotic deformities of the spine in ankylosing spondylitis. Long term results from the patient's view-point on the basis of standardized parameters are not available. This was the intention of this study. MATERIAL AND METHODS: From 1979 to 1982 34 patients underwent surgical correction of a flexion deformity of the spine in ankylosing spondylitis. Correction was achieved with four v-shaped lumbar osteotomies using Harrington's compression system. Seven to ten years postoperatively the patients were asked to answer a questionnaire containing the Mopo-scales and a few additional questions in order to compare the patients pre- and postoperative status and evaluate the long-term quality of the operative procedure. The Mopo-scales exist of the 8 subscales mobility, physical-, daily-, household-, social activity, pain, depression, anxiety with 60 questions (items). The statistical analysis was carried out with the Wilcoxon- and Chi-Square-test using a level of significance of p < n =" 47)" style="font-weight: bold;">A new approach to defining functional ability in ankylosing spondylitis: the development of the Bath Ankylosing Spondylitis Functional Index.
Calin A, Garrett S, Whitelock H, Kennedy LG, O'Hea J, Mallorie P, Jenkinson T.
J Rheumatol. 1994 Dec;21(12):2281-5.
Royal National Hospital for Rheumatic Diseases, Bath, UK.
OBJECTIVE. After pain and stiffness, one of the most important complaints of patients with ankylosing spondylitis (AS) is disability. The main aims of treatment are to control pain but also to improve function. Various methods of assessing function exist but are either not specific for the disease or have not been adequately validated. As a result of this deficiency we developed the Bath Ankylosing Spondylitis Functional Index (BASFI) as a new approach to defining and monitoring functional ability in patients with AS. METHODS. This self-assessment instrument was designed by a team of medical professionals in conjunction with patients, and consists of 8 specific questions regarding function in AS and 2 questions reflecting the patient's ability to cope with everyday life. Each question is answered on a 10 cm horizontal visual analog scale, the mean of which gives the BASFI score (0-10). The questionnaire was completed 257 times in total: once by 116 outpatients and by 47 inpatients on 3 occasions over a 3-week intensive physiotherapy course. In addition, the instrument was compared with the Dougados functional index. RESULTS. Patients scores covered 95% of the BASFI range, giving a normal distribution of results. In contrast only 65% of the Dougados functional index scale was used. Furthermore, over the 3 week period of inpatient treatment, the BASFI revealed a significant improvement in function (20%, p = 0.004) while there was a less impressive change in the Dougados functional index (6%, p = 0.03). This demonstrates the superior sensitivity of the BASFI. Consistency was good for both indices (p < style="font-weight: bold;">Comparison between self-report measures and clinical observations of functional disability in ankylosing spondylitis, rheumatoid arthritis and fibromyalgia.
Hidding A, van Santen M, De Klerk E, Gielen X, Boers M, Geenen R, Vlaeyen J, Kester A, van der Linden S.
J Rheumatol. 1994 May;21(5):818-23.
Department of Internal Medicine, University Hospital, Maastricht, The Netherlands.
OBJECTIVE. To study concordance between self-report measures and clinical observations of functional disability in ankylosing spondylitis (AS), rheumatoid arthritis (RA), and fibromyalgia (FM). METHODS. 35 patients with AS completed 9 selected items of the Functional Index questionnaire, whereas 12 patients with RA and 13 with FM completed 7 selected items of the Arthritis Impact Measurement Scales. Five days later, all 60 patients and 4 controls actually performed the selected activities, which were recorded on video. The tapes were assessed in random order by 12 observers (6 occupational therapists and 6 physicians). Both patients and observers indicated functional disability on a 10 cm visual analog scale (VAS). RESULTS. Interobserver agreement was high (Cronbach's alpha 0.98). All observers scored the 4 healthy controls as having no disability at all. Mean discordance scores (VAS patients minus VAS observers) for the selected items were negligible in AS [-0.17 cm (p = 0.30)], moderate in RA [+1.10 cm (p = 0.06)] and high in FM [+2.44 cm (p < style="font-weight: bold;">Long-term disability and prolonged sick leaves as outcome measurements in ankylosing spondylitis. Possible predictive factors.
Guillemin F, Briançon S, Pourel J, Gaucher A.
Arthritis Rheum. 1990 Jul;33(7):1001-6.
Clinique de Rhumatologie, CHU de Nancy, France.
Prognostic factors for the occurrence of longterm disability and prolonged sick leave were determined in 182 patients with ankylosing spondylitis. A significant relationship appeared between functional disability (determined by the Stanford Health Assessment Questionnaire) and sex, age at disease onset, and the number of peripheral joints involved. Using a life-table approach, the probability of prolonged sick leaves was associated with peripheral joint involvement and work that involved carrying heavy loads. Long-term disability was more frequent after work involving exposure to cold conditions (relative risk [RR] = 2.01) and prolonged standing postures (RR = 1.34), while sedentary work (RR = 0.35) and formal vocational rehabilitation programs (RR = 0.57) seemed to protect against long-term disability.

[Occupational rehabilitation of patients with ankylosing spondylitis]
Baumann P, Riede D.
Z Gesamte Hyg. 1988 Jul;34(7):426-7.
[Article in German]

Evaluation of a functional index and an articular index in ankylosing spondylitis.
Dougados M, Gueguen A, Nakache JP, Nguyen M, Mery C, Amor B.
J Rheumatol. 1988 Feb;15(2):302-7.
Rheumatology Clinic, Hôpital Cochin, Paris, France.
We describe an index of functional impairment and a system of scoring joint tenderness for use in the assessment of ankylosing spondylitis. The functional index consists of 20 questions and the articular index is based on the scoring of a total of 10 joint responses after movement or firm digital pressure. These indices are simple to establish and not time consuming. They have a high degree of intra- and interobserver reproducibility. The indices showed changes in short term clinical trials of antiinflammatory drugs; these changes were highly correlated with the patient's overall assessment of his own clinical condition.

A review of 100 patients with ankylosing spondylitis with particular reference to socio-economic effects.
Wordsworth BP, Mowat AG.
Br J Rheumatol. 1986 May;25(2):175-80.
One hundred patients with ankylosing spondylitis of at least 5 years' duration were interviewed and examined. In addition to musculoskeletal symptoms, 11 subjects had evidence of a variety of neurological complaints. Nine were unemployed and only nine of the remainder felt the disease had seriously affected their employment. One third of patients had been off work for more than 2 months in the course of the disease but frequently due to associated illness. Most patients did not experience disability with household activities but peripheral joint involvement or serious spinal stiffness increased this risk. Symptoms referrable to athletic pursuits may have first drawn attention to the disease in some individuals and sporting activities were curtailed at a younger age than in controls. Driving caused difficulties in up to 50% of subjects due to poor all-round vision. Cervical spine fractures occurred in two patients.

[Work capacity and disability in the long-term treatment of patients with rheumatoid arthritis and ankylosing spondylarthritis]
Trofimova TM, Alekberova ZS, Surovtseva VM, Polianskaia IP, Tarasenkova TA.
Ter Arkh. 1984;56(5):62-6.
[Article in Russian]

[Evaluation of the degree of invalidation of ankylosing spondylitis]
Schmitt E.
Lebensversicher Med. 1983 Aug 26;35(7):149-51.
[Article in German]

Working ability of 76 patients with ankylosing spondylitis.
Lehtinen K.
Scand J Rheumatol. 1981;10(4):263-5.
The working ability of 76 patients with ankylosing spondylitis (AS) diagnosed between 1952 and 1959 was investigated. After 25 years of AS, 48% of the patients were still able to work at their original occupation and only 30% were unable to work at all. 17% of the patients had had to change their occupation and 5% had retired because of age. This finding does not differ from those reported in earlier studies.

[Disability evaluation in cases of patients with rheumatoid arthritis and ankylosing spondylitis based on the records of the Provincial Outpatient Rheumatology Clinic at Bydgoszcz]
Sadkiewicz S.
Reumatologia. 1974;12(2):139-46.
[Article in Polish]

[The problem of disability in Bechterew's disease]
Sit'aj S, Svec V, Hudáková G, Sípos J.
Fysiatr Revmatol Vestn. 1967 Aug;45(4):204-8.
[Article in Slovak]

[DETERMINATION OF WORK CAPACITY IN SOME RHEUMATIC DISEASES.]
DUERRIGL T.
Lijec Vjesn. 1964 Jan;86:55-61.
[Article in Undetermined]

[CLINICAL ASPECTS, SOCIAL SIGNIFICANCE AND EVALUATION OF DEFORMING ARTHROSES.]
PROCHAZKA J.
Acta Chir Orthop Traumatol Cech. 1963 Apr;30:153-60.
[Article in Czech]

[WORKING EFFICIENCY OF THE MOTOR APPARATUS OF SPONDYLOARTHRITIS ANKYLOPOIETICA PATIENTS ACCORDING TO CLINICAL AND RADIOLOGICAL DATA.]
JESZKE W.
Reumatologia. 1963;14:147-50.
[Article in Polish]

[Spondylarthritis ankylopoetica and war injury.]
TREIBER W.
Munch Med Wochenschr. 1962 Nov 30;104:2335-40.
[Article in German]

[Medical-industrial expert testimony and working capacity in ankylosing spondyloarthritis.]
ZINOV'EVA LS.
Ortop Travmatol Protez. 1958 Jan-Feb;19(1):48-50.
[Article in Russian]