BACKGROUND: We recently developed a model of stratified exercise therapy, consisting of (i) a stratification algorithm allocating patients with knee osteoarthritis (OA) into one of the three subgroups ('high muscle strength subgroup' representing a post-traumatic phenotype, 'low muscle strength subgroup' representing an age-induced phenotype, and 'obesity subgroup' representing a metabolic phenotype) and (ii) subgroup-specific exercise therapy. In the present study, we aimed to test the construct validity of this algorithm.METHODS: Data from five studies (four exercise therapy trial cohorts and one cross-sectional cohort) were used to test the construct validity of our algorithm by 63 a priori formulated hypotheses regarding three research questions: (i) are the proportions of patients in each subgroup similar across cohorts? (15 hypotheses); (ii) are the characteristics of each of the subgroups in line with their proposed underlying phenotypes? (30 hypotheses); (iii) are the effects of usual exercise therapy in the 3 subgroups in line with the proposed effect sizes? (18 hypotheses).RESULTS: Baseline data from a total of 1211 patients with knee OA were analyzed for the first and second research question, and follow-up data from 584 patients who were part of an exercise therapy arm within a trial for the third research question. In total, the vast majority (73%) of the hypotheses were confirmed. Regarding our first research question, we found similar proportions in each of the three subgroups across cohorts, especially for three cohorts. Regarding our second research question, subgroup characteristics were almost completely in line with the proposed underlying phenotypes. Regarding our third research question, usual exercise therapy resulted in similar, medium to large effect sizes for knee pain and physical function for all three subgroups.CONCLUSION: We found mixed results regarding the construct validity of our stratification algorithm. On the one hand, it is a valid instrument to consistently allocate patients into subgroups that aligned our hypotheses. On the other hand, in contrast to our hypotheses, subgroups did not differ substantially in effects of usual exercise therapy. An ongoing trial will assess whether this algorithm accompanied by subgroup-specific exercise therapy improves clinical and economic outcomes.
MULTIFILE
Background: Although diagnosing and treating malnutrition, sarcopenia and underweight are recommended to be embedded and sustained within nutritional care, it is unknown if that is facilitated in geriatric rehabilitation. This study determined the proportion of geriatric rehabilitation inpatients with malnutrition, sarcopenia or underweight receiving dietetic interventions as part of routine clinical care and if these patients have greater improvements in body weight and composition compared to patients not receiving dietetic interventions.Methods: Geriatric rehabilitation inpatients from the observational REStORing health of acutely unwell adulTs (RESORT) cohort were included (n=971, median age 83.2 [77.7-88.8] years, 58.5% (n=568) females). Malnutrition, sarcopenia and underweight were defined by the Global Leadership Initiative of Malnutrition, European Working Group on Sarcopenia in Older People 2 and age-specific body mass index cut-offs. Data on dietetic interventions initiated by dietitians as part of clinical care was extracted from the centralised hospital database. Changes in body weight (kg), skeletal muscle mass (kg, %), and fat mass (kg, %) from admission to discharge were determined using linear mixed models.Results: Dietetic interventions were received by 306 (62.0%), 138 (71.5%) and 153 (76.9%) of patients with malnutrition (n=493), sarcopenia (n=193) and underweight (n=199). Duration and frequency of dietetic interventions were higher in patients with malnutrition, sarcopenia or underweight compared to patients without those conditions. There were no differences in body weight/composition changes in patients with malnutrition, sarcopenia or underweight receiving dietetic interventions compared to those not receiving interventions.Conclusions: One-third of geriatric rehabilitation inpatients with malnutrition, sarcopenia or underweight are not receiving dietetic interventions and therefore the referral and diagnostic process require improvements. Patients with malnutrition, sarcopenia or underweight receiving dietetic interventions had no greater improvements in body weight/composition compared to those who did not receive interventions. Tailoring dietetic interventions for malnutrition, sarcopenia and underweight diagnosis may improve patient outcomes.
MULTIFILE
ObjectivesOsteoarthritis (OA) of the foot-ankle complex is understudied. Understanding determinants of pain and activity limitations is necessary to improve management of foot OA. The aim of the present study was to investigate demographic, foot-specific and comorbidity-related factors associated with pain and activity limitations in patients with foot OA.MethodsThis exploratory cross-sectional study included 75 patients with OA of the foot and/or ankle joints. Demographic and clinical data were collected with questionnaires and by clinical examination. The outcome variables of pain and activity limitations were measured using the Foot Function Index (FFI). Potential determinants were categorized into demographic factors (e.g., age, sex), foot-specific factors (e.g., plantar pressure and gait parameters), and comorbidity-related factors (e.g., type and amount of comorbid diseases). Multivariable regression analyses with backward selection (p-out≥0.05) were performed in two steps, leading to a final model.ResultsOf all potential determinants, nine factors were selected in the first step. Five of these factors were retained in the second step (final model): female sex, pain located in the hindfoot, higher body mass index (BMI), neurological comorbidity, and Hospital Anxiety and Depression Scale (HADS) score were positively associated with the FFI score. The explained variance (R2) for the final model was 0.580 (adjusted R2 = 0.549).ConclusionFemale sex, pain located in the hindfoot, higher BMI, neurological comorbidity and greater psychological distress were independently associated with a higher level of foot-related pain and activity limitations. By addressing these factors in the management of foot OA, pain and activity limitations may be reduced.
