Self-reported painful joint count and assessor-reported tender joint count as instruments to assess pain in hand osteoarthritis.

OBJECTIVES: To evaluate self-reported and assessor-reported joint counts for pain and their value in measuring pain and joint activity in hand OA patients. METHODS: A total of 524 patients marked painful joints on hand diagrams. Nurses assessed tenderness upon palpation. Pain was measured with a visual analogue scale pain and the Australian/Canadian hand OA index subscale pain. Synovitis and bone marrow lesions in right hand distal/proximal interphalangeal joints on MRI served as measure of joint activity. Agreement was assessed on the patient (intraclass correlation coefficient, Bland-Altman plot) and joint level (percentage absolute agreement). Correlations with measures of pain and joint activity were analysed, and joint level associations with synovitis/bone marrow lesions were calculated. RESULTS: Self-reported painful joint count (median 8, interquartile range 4-13) was consistently higher than assessor-reported tender joint count (3, 1-7). Agreement between patients and nurses on overall scores was low. Percentage absolute agreement on the joint level was 61-89%. Joint counts correlated similarly but weakly with measures of pain and joint activity (r = 0.14-0.38). On the joint level, assessor-reported tenderness was more strongly associated with synovitis/bone marrow lesions than self-reported pain. CONCLUSION: In hand OA, self- and assessor-reported joint counts cannot be used interchangeably, and measure other pain aspects than questionnaires. Assessor-reported tenderness was most closely related to MRI-defined joint activity.

Illness perceptions and their association with 2 year functional status and change in patients with hand osteoarthritis.

Objective: To investigate the association between illness perceptions and disability both cross-sectionally and over 2 years in patients with hand OA. Methods: Illness perceptions and self-reported disability were assessed at baseline and after 2 years in 384 patients with primary hand OA (mean age 61 years, 84% women, n = 312 with follow-up) with the Illness Perception Questionnaire - Revised (IPQ-R), Functional Index for Hand OA, Australian/Canadian Hand OA Index and HAQ. Risk ratios for high disability (highest quartile) at both time points were estimated for tertiles of IPQ-R dimensions, using Poisson regression. The mean IPQ dimension change difference between patients with and without disability progression (change Functional Index for Hand OA ⩾ 1, Australian/Canadian Hand OA Index > 1.4, HAQ > 0.22) was estimated with linear regression. Analyses were adjusted for age, Doyle index and baseline score. Results: At baseline, stronger negative illness perceptions were associated with high disability. Baseline illness perceptions were also associated with high disability after 2 years, although adjustment made apparent that these associations were confounded by baseline disability status. Most illness perceptions changed over 2 years; understanding increased, OA was regarded as more chronic and fewer emotions and consequences and less personal and treatment control were experienced. The 2 year change in disability was different between patients with and without progression for the illness perceptions of more perceived consequences, symptoms, treatment control and emotions. Conclusion: Illness perceptions seemed to be implicated in disability and its progression. Our results suggest that interventions could focus on improving baseline disability, potentially using illness perceptions to accomplish this goal.

Validity, reliability, responsiveness and feasibility of four hand mobility measures in hand osteoarthritis.

OBJECTIVES: To investigate metric properties of four hand mobility tests in hand OA patients, using the OMERACT filter. METHODS: Trained assessors examined the Hand Mobility in Scleroderma test (HAMIS), fingertip-to-palm distance (FPD), modified Kapandji index (MKI) and number of hand joints with limited mobility in participants from two cohorts [Genetics ARthrosis and Progression (n = 207) and Hand OSTeoArthritis in Secondary care (n = 174)]. Validity was appraised by assessment of correlations with other outcome measures, and ability to measure thumb vs finger mobility specifically, using cumulative probability plots. The proportion of participants changing in hand mobility based on the smallest detectable difference was calculated for responsiveness. Intraclass correlation coefficients (ICCs) for intra- and interobserver reliability, and feasibility (time to perform tests) were studied in a random sample (n = 20). RESULTS: Participants displayed large variation in mobility scores. Strongest correlations were observed with structural damage (rs = 0.43-0.52) and bony swelling (rs = 0.46-0.58); correlation patterns were similar among tests. HAMIS, FPD and MKI could all measure finger mobility specifically, but only HAMIS measured thumb mobility particularly. Interobserver reliability was best for HAMIS, ICC 0.90 (95% CI: 0.76, 0.96); intraobserver reliability was excellent for all (ICCs 0.94-0.97). In 2 years, little change was observed; HAMIS was the most sensitive-to-change (smallest detectable difference 3.7% of maximum score). The mean performance time ranged from 0.7 (s.d. 0.5, for FPD) to 5.7 (s.d. 1.3, for HAMIS) min. CONCLUSION: HAMIS, FPD, MKI and number of joints with limited mobility are all valid, reliable and feasible measures for assessing hand mobility in hand OA, although HAMIS had slightly more favourable properties. Studies assessing sensitivity-to-change in a clinical trial setting are warranted.

Coping styles and disability in patients with hand osteoarthritis.

OBJECTIVE: Coping responses have been shown to determine health outcomes in chronic diseases. The aim of the study was to examine the role of joint-specific factors and coping styles on disability in patients with hand OA. METHODS: Primary hand OA patients who consulted secondary care, underwent physical examination to assess the number of joints with bony joint enlargements, pain upon palpation, soft tissue swelling, deformities and limitations in motion. Coping styles were assessed with Coping with Rheumatic Stressors. Disability (score ≥5) was assessed by the Functional Index for Hand OA (possible score 0-30) cross-sectionally and after 1 year. With multivariate logistic regression, joint-specific variables and coping styles were associated with disability cross-sectionally and after 1 year, adjusted for age, sex and BMI. RESULTS: A total of 314 patients (88% women, mean age 61.4 years) were included in the cross-sectional analyses; 68% were considered as disabled. Longitudinal data after 1 year were available in 173 patients (71% disabled). In multivariate analysis including all joint-specific factors, only painful joints and joints with limitations in motion were associated with disability. Disadvantageous scores for the coping scales (comforting cognitions, decreasing activity and pacing) were positively associated with disability cross-sectionally. Disability after 1 year was only associated with the coping scales decreasing activity and pacing. Joint-specific factors were also associated with disability, independent of coping styles. CONCLUSION: In patients with hand OA, joint-specific factors and coping styles decreasing activity and pacing were both associated with disability. Our results suggest that interventions should aim at joint-specific complaints as well as changing coping styles to improve functional outcome.

Hand osteoarthritis is associated with limitations in paid and unpaid work participation and related societal costs: the HOSTAS cohort.

OBJECTIVES: Data on work participation impairment and related societal costs for patients with hand osteoarthritis (OA) are scarce. Therefore, we aimed to investigate the association of hand OA with work limitations and costs of productivity loss in paid and unpaid work. METHODS: We used data from the Hand Osteoarthritis in Secondary Care cohort, including patients with hand OA diagnosed by their treating rheumatologist. Using the validated Health and Labour Questionnaire, we assessed experienced unpaid and paid work restrictions, unpaid work replacement by others and inefficiency and absence during paid work related to hand OA over the last 2 weeks. Societal costs (€) per hour of paid and unpaid work were estimated using Dutch salary data in 2019. RESULTS: 381 patients were included (mean age 61 years, 84% women, 26% high education level, 55% having any comorbidity). Replacement of unpaid work by others due to hand OA was necessary for 171 out of 381 patients (45%). Paid work was reported by 181/381 patients (47%), of whom 13/181 (7%) reported absenteeism, 28/181 (15%) unproductive hours at work and 120/181 (66%) paid work restrictions due to hand OA.Total estimated work-related societal costs per patient with hand OA (381 patients) were €94 (95% CI 59 to 130) per 2 weeks (€2452, 95% CI 1528 to 3377 per year). CONCLUSIONS: Hand OA is associated with impairment in paid and unpaid work participation, which translates into substantial societal costs of lost productivity. These results highlight the importance of adequate hand OA treatment.

Health-related Quality of Life in Patients with Hand Osteoarthritis from the General Population and the Outpatient Clinic.

OBJECTIVE: To investigate the association of hand osteoarthritis (OA) and concurrent hand and knee OA with health-related quality of life (HRQOL) in the general population, and in patients consulting a rheumatology outpatient clinic. METHODS: In the population-based Netherlands Epidemiology of Obesity (NEO) study, participants were recruited from the greater area of Leiden, the Netherlands. In the Hand OSTeoArthritis in Secondary care (HOSTAS) study, patients with a rheumatologist's diagnosis of hand OA were recruited from a Leiden-based hospital. In both cohorts, hand and knee OA were defined by the American College of Rheumatology clinical criteria. In NEO, self-reported hospital-based specialist consultation for OA was recorded. Physical and mental HRQOL was assessed with normalized Medical Outcomes Study Short Form-36 scores. Associations were analyzed using linear regression, adjusted for age, sex, education, ethnicity, and body mass index. RESULTS: Hand OA alone and concurrent hand and knee OA was present in 8% and 4% of 6334 NEO participants, and in 57% and 32% of 538 HOSTAS patients. In NEO, hand OA alone, and concurrent hand and knee OA, were associated with lower physical component summary (PCS) scores [mean difference -2.4 (95% CI -3.6, -1.3) and -7.7 (95% CI -9.3, -6.2), respectively] compared with no OA. Consulting a specialist was associated with worse PCS scores. In the HOSTAS cohort, mean PCS scores were lower than norm values (-3.5 and -7.9 for hand OA and combined OA, respectively). Mental HRQOL was not clinically relevantly associated in either cohort. CONCLUSION: Hand OA was associated with reduced physical, but not mental, HRQOL in the general population and hospital patients. Physical HRQOL was further reduced in hospital care, and with concurrent knee OA.

Do Comorbidities Play a Role in Hand Osteoarthritis Disease Burden? Data from the Hand Osteoarthritis in Secondary Care Cohort.

OBJECTIVE: Because the association and its clinical relevance between comorbidities and primary hand osteoarthritis (OA) disease burden is unclear, we studied this in patients with hand OA from our Hand OSTeoArthritis in Secondary care (HOSTAS) cohort. METHODS: Cross-sectional data from the HOSTAS study were used, including consecutive patients with primary hand OA. Nineteen comorbidities were assessed: 18 self-reported (modified Charlson index and osteoporosis) and obesity (body mass index ≥ 30 kg/m2). Mean differences were estimated between patients with versus without comorbidities, adjusted for age and sex: for general disease burden [health-related quality of life (HRQOL), Medical Outcomes Study Short Form-36 physical component scale (0-100)] and disease-specific burden [self-reported hand function (0-36), pain (0-20; Australian/Canadian Hand OA Index), and tender joint count (TJC, 0-30)]. Differences above a minimal clinically important improvement/difference were considered clinically relevant. RESULTS: The study included 538 patients (mean age 61 yrs, 86% women, 88% fulfilled American College of Rheumatology classification criteria). Mean (SD) HRQOL, function, pain, and TJC were 44.7 (8), 15.6 (9), 9.3 (4), and 4.8 (5), respectively. Any comorbidity was present in 54% (287/531) of patients and this was unfavorable [adjusted mean difference presence/absence any comorbidity (95% CI): HRQOL -4.4 (-5.8 to -3.0), function 1.9 (0.4-3.3), pain 1.4 (0.6-2.1), TJC 1.3 (0.4-2.2)]. Number of comorbidities and both musculoskeletal (e.g., connective tissue disease) and nonmusculoskeletal comorbidities (e.g., pulmonary and cardiovascular disease) were associated with disease burden. Associations with HRQOL and function were clinically relevant. CONCLUSION: Comorbidities showed clinically relevant associations with disease burden. Therefore, the role of comorbidities in hand OA should be considered when interpreting disease outcomes and in patient management.