Trajectories of Physical Work Capacity in Early Symptomatic Osteoarthritis of Hip and Knee: Results from the Cohort Hip and Cohort Knee (CHECK) Study.

Purpose To evaluate the 5-year course of physical work capacity of participants with early symptomatic osteoarthritis (OA) of the hip and/or the knee; to identify trajectories and explore the relationship between trajectories and covariates. Methods In a prospective cohort study, physical work capacity was measured at baseline, using a test protocol (functional capacity evaluation) consisting of work-related physical activities. Participants were invited to participate in 1, 2 and 5 year follow-up measurements. Multilevel analysis and latent classes analysis were performed, in models with test performances as dependent variables and age, sex, work status, self-reported function (Western Ontario McMasters Arthritis Scale-WOMAC), body mass index (BMI) and time as independent variables. Multiple imputation was used to control for the influence of missing data. Results At baseline and after 1, 2 and 5 years there were 96, 64, 61 and 35 participants. Mean (SD) age at baseline was 56 (4.9) years, 84% were females. There was no statistically significant change in test performances (lifting low and high, carrying, static overhead work, repetitive bending, repetitive rotations) between the 4 measurements. Male sex, younger age and better self-reported function were statistically significant (p < 0.05) determinants of higher performance on most of the tests; having a paid job, BMI and progression of time were not. Three trajectories were identified: 'weak giving way', 'stable and able', and 'strong with decline'. Discussion In subgroups of participants with early symptomatic OA, determined by age, sex and self-reported function, physical work capacity seems to be a stable characteristic over 5 years.

Functional capacity of people with early osteoarthritis: a comparison between subjects from the cohort hip and cohort knee (CHECK) and healthy ageing workers.

OBJECTIVE: The prevalence of osteoarthritis (OA) increases, but the impact of the disorder on peoples' functional capacity is not known. Therefore, the objective of this study was to compare self-reported health status and functional capacity of subjects with early OA of hip and/or knee to reference data of healthy working subjects and to assess whether this capacity is sufficient to meet physical job demands. METHODS: Self-reported health status and functional capacity of 93 subjects from the Cohort Hip and Cohort Knee (CHECK) were measured using the Short-Form 36 Health Survey and 6 tests of the Work Well Systems Functional Capacity Evaluation. Results were compared with reference data from 275 healthy workers, using t-tests. To compare the functional capacity with job demands, the proportions of subjects with OA performing lower than the p(5) of reference data were calculated. RESULTS: Compared to healthy workers, the subjects (mean age 56) from CHECK at baseline reported a significantly worse physical health status, whereas the women (n = 78) also reported a worse mental health status. On the FCE female OA subjects performed significantly lower than their healthy working counterparts on all 6 tests. Male OA subjects performed lower than male workers on 3 tests. A substantial proportion of women demonstrated functional capacities that could be considered insufficient to perform jobs with low physical demands. CONCLUSIONS: Functional capacity and self-reported health of subjects with early OA of the hips and knees were worse compared to healthy ageing workers. A substantial proportion of female subjects did not meet physical job demands.

Work participation and health status in early osteoarthritis of the hip and/or knee: a comparison between the Cohort Hip and Cohort Knee and the Osteoarthritis Initiative.

OBJECTIVE: To examine the work participation of Dutch people with early osteoarthritis (OA) in hips or knees and compare this with data from the American Osteoarthritis Initiative (OAI) cohort. The influence of health status and personal factors on work participation was analyzed. METHODS: In the Cohort Hip and Cohort Knee (CHECK) study, 1,002 subjects were included. Baseline questionnaire data from 970 subjects were analyzed. Rate ratios were calculated to compare work participation with the general Dutch population, after correcting (by stratifying) for age, sex, and education. Health status was measured using the Short Form 36 health survey and the Western Ontario and McMaster Universities Osteoarthritis Index. Groups were compared (CHECK versus OAI, workers versus nonworkers) using t-tests. RESULTS: The mean age of the subjects was 56 years and 79% were women. Overall participation was 51%, similar to the general Dutch population and lower than in the OAI (76%). Point prevalence of sick leave because of hip/knee symptoms was 2%, and year prevalence was 12%. Of the subjects, 14% had made work adaptations. Workers reported significantly better health status (corrected for age, sex, and education) than nonworkers. CONCLUSION: Work participation of Dutch people with early OA is similar to the general population and significantly lower than American subjects. Increasing age, female sex, and lower education level were related to lower participation. Societal factors appear to have had more effect on work participation than health status in this stage of OA. The better health status of workers could not be explained solely by selection bias, but may be a result of work.

Self-reported functional status as predictor of observed functional capacity in subjects with early osteoarthritis of the hip and knee: a diagnostic study in the CHECK cohort.

OBJECTIVES: Patients with hip or knee osteoarthritis (OA) may experience functional limitations in work settings. In the Cohort Hip and Cohort Knee study (CHECK) physical function was both self-reported and measured performance-based, using Functional Capacity Evaluation (FCE). Relations between self-reported scores on SF-36 and WOMAC (Western Ontario and McMaster Arthritis Index, function scales) and FCE performance were studied, and their diagnostic value for clinicians in predicting observed physical work limitations was assessed. METHODS: Ninety-two subjects scored physical function on SF-36 (scale 0-100, 100 indicating the best health level) and WOMAC (scale 0-68, 68 indicates maximum restriction) and performed the FCE. Correlations were calculated between all scores. Cross-tables were constructed using both questionnaires as diagnostic tests to identify work limitations. Subjects lifting <22.5 kg on the FCE-test 'lifting-low' were labeled as having physical work limitations. Diagnostic aspects at different cut-off scores for both questionnaires were analysed. RESULTS: Statistically significant correlations (Spearman's rho 0.34-0.49) were found between questionnaire scores and lifting and carrying tests. Results of a diagnostic cross-table with cut-off point <60 on SF-36 'physical functioning' were: sensitivity 0.34, specificity 0.97 and positive predictive value (PV+) 0.95. Cut-off point > or =21 on WOMAC 'function' resulted in sensitivity 0.51, specificity 0.88 and PV+ 0.88. CONCLUSION: Low self-reported function scores on SF-36 and WOMAC diagnosed subjects with limitations on the FCE. However, high scores did not guarantee performance without physical work limitations. These results are specific to the tested persons with early OA, in populations with a different prevalence of limitations, different diagnostic values will be found. FCE may be indicated to help clinicians to assess actual work capacity.

Functional capacity evaluation in subjects with early osteoarthritis of hip and/or knee; is two-day testing needed?

INTRODUCTION: The Work Well Functional Capacity Evaluation (WW FCE) is a two-day performance based test consisting of several work-related activities. Three lifting and carrying test items may be performed on both days. The objective of this study was to assess the need for repeated testing of these items in subjects with early osteoarthritis of the hip and/or the knee and to analyze sources of variation between the 2 days of measurement. METHODS: A standardized WW FCE protocol was applied, including repeated testing of lifting low, lifting overhead and carrying. Differences and associations between the 2 days were calculated using paired samples t-tests, intraclass correlation coefficients (ICC) and limits of agreement (LoA). Possible sources of individual variation between the 2 days were identified by Wilcoxon signed ranks tests. Pearson correlation coefficients were calculated for differences in performances between days and differences in possible sources of variation between days. RESULTS: Seventy-nine subjects participated in this study, their mean (SD) age was 56.6 (4.8) years, median (min-max) WOMAC (Western Ontario and McMaster Universities) index scores for pain, stiffness and physical function were 5 (0-17), 3 (0-7) and 14 (0-49), respectively. Median (min-max) SF36 physical function was 75 (5-95), and SF36 pain score was 67 (12-76). Mean performance differences ranged from -0.2 to -0.8 kg (P > 0.05). ICC's ranged from 0.75 (lifting overhead) to 0.88 (lifting low). LoA were: lifting low 8.0 kg; lifting overhead 6.5 kg; carrying 9.0 kg. Pearson's correlations were low and non-significant. CONCLUSIONS: All three tests show acceptable two-day consistency. WW FCE testing on two consecutive days is not necessary for groups of subjects with early osteoarthritis. Individual sources of variation could not be identified.