Assistive walking device use and knee osteoarthritis: results from the Health, Aging and Body Composition Study (Health ABC Study).

OBJECTIVES: To identify factors that predicted incident use of assistive walking devices (AWDs) and to explore whether AWD use was associated with changes in osteoarthritis of the knee. DESIGN: Prospective cohort study. SETTING: Community. PARTICIPANTS: Older adults (N=2639) in the Health, Aging and Body Composition (Health ABC) Study including a subset of 874 patients with prevalent knee pain. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Incident use of AWDs, mean Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain scores, and the frequency of joint space narrowing on knee radiographs over a 3-year time period. RESULTS: AWD use was initiated by 9% of the entire Health ABC cohort and 12% of the knee pain subset. Factors that predicted use in both groups were age ≥73 (entire cohort: odds ratio [OR]=2.07; 95% confidence interval [CI], 1.43-3.01; knee pain subset: OR=1.87; 95% CI, 1.16-3.03), black race (entire cohort: OR=2.95; 95% CI, 2.09-4.16; knee pain subset: OR=3.21; 95% CI, 2.01-5.11), and lower balance ratios (entire cohort: OR=3.18; 95% CI, 2.21-4.59; knee pain subset: OR=3.77; 95% CI, 2.34-6.07). Mean WOMAC pain scores decreased slightly over time in both AWD and non-AWD users. Twenty percent of non-AWD users and 28% of AWD users had radiographic progression in joint space narrowing of the tibiofemoral joint in at least 1 knee. Fourteen percent of non-AWD users and 12% of AWD users had radiographic progression in joint space narrowing in the patellofemoral joint in at least 1 knee. CONCLUSIONS: AWDs are frequently used by older adults. Knee pain and balance problems are significant reasons why older adults initiate use of an AWD. In an exploratory analysis, there was no consistent relation between the use or nonuse of an AWD and WOMAC pain scores or knee joint space narrowing progression. Further studies of the relation of use of AWDs to changes in knee osteoarthritis are needed.

Relationship of meeting physical activity guidelines with quality-adjusted life-years.

OBJECTIVE: The quality-adjusted life-year (QALY) is a standard outcome measure used in cost-effectiveness analyses. This study investigates whether attainment of federal physical activity guidelines is associated with higher QALY estimates among adults with or at an increased risk for knee osteoarthritis. METHODS: This is a prospective study of 1794 Osteoarthritis Initiative participants. Physical activity was measured using accelerometers at baseline. Participants were classified as (1) Meeting Guidelines [≥150min of moderate-to-vigorous (MV) activity per week acquired in sessions ≥10min], (2) Insufficiently Active (≥1 MV session[s]/week but below the guideline), or (3) Inactive (zero MV sessions/week). A health-related utility score was derived from participant responses to the 12-item Short-Form Health Survey at baseline and 2 years later. The QALY was calculated as the area under utility curve over 2 years. The relationship of physical activity level to median QALY adjusted for socioeconomic and health factors was estimated using quantile regression. RESULTS: Relative to the Inactive group, median QALYs over 2 years were significantly higher for the Meeting Guidelines (0.112, 95% CI: 0.067-0.157) and Insufficiently Active (0.058, 95% CI: 0.028-0.088) groups, controlling for socioeconomic and health factors. CONCLUSION: We found a significant graded relationship between greater physical activity level and higher QALYs. Using the more conservative estimate of 0.058, if an intervention could move someone out of the Inactive group and costs <$2900 over 2 years, it would be considered cost effective. Our analysis supports interventions to promote physical activity even if recommended levels are not fully attained.

Relationship of meeting physical activity guidelines with health-related utility.

OBJECTIVE: Health-related utility measures overall health status and quality of life and is commonly incorporated into cost-effectiveness analyses. This study investigates whether attainment of federal physical activity guidelines translates into better health-related utility in adults with or at risk for knee osteoarthritis (OA). METHODS: Cross-sectional data from 1,908 adults with or at risk for knee OA participating in the accelerometer ancillary study of the Osteoarthritis Initiative were assessed. Physical activity was measured using 7 days of accelerometer monitoring and was classified as 1) meeting guidelines (≥150 bouted moderate-to-vigorous [MV] minutes per week); 2) insufficiently active (≥1 MV bout[s] per week but below guidelines); or 3) inactive (zero MV bouts per week). A Short Form 6D health-related utility score was derived from patient-reported health status. Relationship of physical activity levels to median health-related utility adjusted for socioeconomic and health factors was tested using quantile regression. RESULTS: Only 13% of participants met physical activity guidelines, and 45% were inactive. Relative to the inactive group, median health-related utility scores were significantly greater for the meeting guidelines group (0.063; 95% confidence interval [95% CI] 0.055, 0.071) and the insufficiently active group (0.059; 95% CI 0.054, 0.064). These differences showed a statistically significant linear trend and strong cross-sectional relationship with physical activity level even after adjusting for socioeconomic and health factors. CONCLUSION: We found a significant positive relationship between physical activity level and health-related utility. Interventions that encourage adults, including persons with knee OA, to increase physical activity even if recommended levels are not attained may improve their quality of life.

Racial disparities in the monitoring of patients on chronic opioid therapy.

Despite well-documented racial disparities in prescribing opioid medications for pain, little is known about whether there are disparities in the monitoring and follow-up treatment of patients who are prescribed opioid medications. We conducted a retrospective cohort study to examine whether there are racial differences in the use of recommended opioid monitoring and follow-up treatment practices. Our sample included 1646 white and 253 black patients who filled opioid prescriptions for noncancer pain for ≥ 90 consecutive days at the Veterans Affairs Pittsburgh Healthcare System pharmacy in fiscal years 2007 and 2008. Several opioid monitoring and follow-up treatment practices were extracted from electronic health records for a 12-month follow-up period. Findings indicated that 26.3% of patients had opioid agreements on file, pain was documented in 71.7% of primary care follow-up visits, urine drug tests were administered to 49.3% of patients, and 21.2% and 4.2% of patients were referred to pain and substance abuse specialists, respectively. Racial differences were observed in several of these practices. In adjusted comparisons, pain was documented less frequently for black patients than for white patients. Among those who had at least 1 urine drug test, black patients were subjected to more tests, especially if they were on higher doses of opioids. Compared with white patients, black patients were less likely to be referred to a pain specialist and more likely to be referred for substance abuse assessment. Addressing disparities in opioid monitoring and follow-up treatment practices may be a previously neglected route to reducing racial disparities in pain management.