Application of Heterogeneity of Treatment-Effects Methods: Exploratory Analyses of a Trial of Exercise-Based Interventions for Knee Osteoarthritis

Objective: To evaluate heterogeneity of treatment effects in a trial of exercise-based interventions for knee osteoarthritis (OA). Methods: Participants (n = 350) were randomized to standard physical therapy (PT; n = 140), internet-based exercise training (IBET; n = 142), or wait list (WL; n = 68) control. We applied qualitative interaction trees (QUINT), a sequential partitioning method, and generalized unbiased interaction detection and estimation (GUIDE), a regression tree approach, to identify subgroups with greater improvements in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score over 4 months. Predictors included 24 demographic, clinical, and psychosocial characteristics. We conducted internal validation to estimate optimism (bias) in the range of mean outcome differences among arms. Results: Both QUINT and GUIDE indicated that for participants with lower body mass index (BMI), IBET was better than PT (improvements of WOMAC ranged from 6.3 to 9.1 points lower), and for those with higher BMI and a longer duration of knee OA, PT was better than IBET (WOMAC improvement was 6.3 points). In GUIDE analyses comparing PT or IBET to WL, participants not employed had improvements in WOMAC ranging from 1.8 to 6.8 points lower with PT or IBT versus WL. From internal validation, there were large corrections to the mean outcome differences among arms; however, after correction, some differences remained in the clinically meaningful range. Conclusion: Results suggest there may be subgroups who experience greater improvement in symptoms from PT or IBET, and this finding could guide referrals and future trials. However, uncertainty persists for specific treatment-effects size estimates and how they apply beyond this study sample

Fall Risk and Utilization of Balance Training for Adults with Symptomatic Knee Osteoarthritis: Secondary Analysis from a Randomized Clinical Trial

Knee osteoarthritis (KOA) is a common disease that hinders activity participation in older adults. Associated symptoms and physiological changes can increase risk of falling in individuals with KOA. Balance training can decrease fall risks in older adults. Limited evidence exists regarding utilization of balance training in physical therapy (PT) for this population. This secondary data analysis investigated the proportion of participants at high risk for falling in the PhysicAl THerapy vs. INternet-based Exercise Training for Patients with Osteoarthritis (PATH-IN) study and the frequency with which balance training was utilized as an intervention in PT. Methods: PATH-IN study participants (N = 344) performed the Four-Stage Balance Test and the Timed Up and Go (TUG) test during baseline assessment. Participants were randomly allocated to PT, an Internet-based exercise program, or a control group. Participants were classified as being at high risk for falling if they did not progress to the single-leg stance (SLS) during the Four-Stage Balance Test, were unable to maintain SLS for 5 seconds, or took longer than 13.5 seconds to complete the TUG test. The proportion of participants at high risk for falling was calculated for all participants and separately for those allocated to PT. In addition, PT notes were coded for balance training and the frequency of balance training utilization was calculated. Results and Discussion: Upon enrollment, 35.5% (N = 122) of all participants and 36.2% (N = 50) of those allocated to PT were at high risk for falling. Of participants allocated to PT with documentation available for coding (N = 118), 35.5% (N = 42) were at high risk for falling. Balance training was provided to 62.7% (N = 74) during at least one PT session. Of those classified as being at high risk for falling, 33.3% (N = 14) did not receive balance training. Conclusions: The finding of high fall risks in more than one-third of all participants with KOA is consistent with previous reports of a higher risk of falling in this population. Many PT participants did receive some balance training; however, one-third of participants at high risk for falling did not. Balance training for individuals with KOA at high risk for falling may be underutilized

Racial Differences in Performance-Based Function and Potential Explanatory Factors Among Individuals With Knee Osteoarthritis

Objective: In individuals with knee osteoarthritis (OA), self-reported physical function is poorer in African Americans than in whites, but whether this difference holds true for objective assessments is unclear. The purpose of this study was to examine racial differences in performance-based physical function as well as potential underlying factors contributing to these racial differences. Methods: Participants with knee OA from a randomized controlled trial completed the 2-minute step test (2MST), timed-up-and-go (TUG), and 30-second chair stand (30s-CST) at baseline. Race differences in performance-based function were assessed by logistic regression. Separate models were adjusted for sets of demographic, socioeconomic, psychological health, and physical health variables. Results: In individuals with knee OA (n = 322; 72% women, 22% African American, mean ± SD age 66 ± 11 years, mean ± SD body mass index 31 ± 8 kg/m2), African Americans (versus whites) had greater unadjusted odds of poorer function (30s-CST odds ratio [OR] 2.79 [95% confidence interval (95% CI) 1.65–4.72], 2MST OR 2.37 [95% CI 1.40–4.03], and TUG OR 3.71 [95% CI 2.16–6.36]). Relationships were maintained when adjusted for demographic and psychological health covariates, but they were either partially attenuated or nonsignificant when adjusted for physical health and socioeconomic covariates. Conclusion: African American adults with knee OA had poorer unadjusted performance-based function than whites. Physical health and socioeconomic characteristics diminished these differences, emphasizing the fact that these factors may be important to consider in mitigating racial disparities in function

Model-based development of a fuzzy logic advisor for artificially ventilated patients

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN041907 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Microdialysis measurement of neurochemical changes in the mediobasal hypothalamus of ovariectomized ewes during oestrus

International audienc

The role of oxytocin release in the mediobasal hypothalamus of the sheep in relation to female sexual receptivity

International audienc

Microdialysis measurement of neurochemical changes in the mediobasal hypothalamus of ovariectomized ewes during oestrus

International audienc