BACKGROUND: Commercial physical activity monitors have wide utility in the assessment of physical activity in research and clinical settings, however, the removal of devices results in missing data and has the potential to bias study conclusions. This study aimed to evaluate methods to address missingness in data collected from commercial activity monitors.

METHODS: This study utilised 1526 days of near complete data from 109 adults participating in a European weight loss maintenance study (NoHoW). We conducted simulation experiments to test a novel scaling methodology (NoHoW method) and alternative imputation strategies (overall/individual mean imputation, overall/individual multiple imputation, Kalman imputation and random forest imputation). Methods were compared for hourly, daily and 14-day physical activity estimates for steps, total daily energy expenditure (TDEE) and time in physical activity categories. In a second simulation study, individual multiple imputation, Kalman imputation and the NoHoW method were tested at different positions and quantities of missingness. Equivalence testing and root mean squared error (RMSE) were used to evaluate the ability of each of the strategies relative to the true data.

RESULTS: The NoHoW method, Kalman imputation and multiple imputation methods remained statistically equivalent (p<0.05) for all physical activity metrics at the 14-day level. In the second simulation study, RMSE tended to increase with increased missingness. Multiple imputation showed the smallest RMSE for Steps and TDEE at lower levels of missingness (<19%) and the Kalman and NoHoW methods were generally superior for imputing time in physical activity categories.

CONCLUSION: Individual centred imputation approaches (NoHoW method, Kalman imputation and individual Multiple imputation) offer an effective means to reduce the biases associated with missing data from activity monitors and maximise data retention.

Background: Prosthetic joint infection (PJI) is the most serious total joint arthroplasty (TJA) complication despite several aseptic and antiseptic preventive measures. There is no clear evidence or even consensus, whether antibiotic-loaded bone cement (ALBC) should be used, in addition to systemic short-term routine antibiotic prophylaxis, to reduce the risk of PJI in primary TJA. We aimed to analyze the efficacy of ALBC for prevention of PJI in patients undergoing primary TJA.

Methods: We searched systematically for randomized controlled trials (RCTs) in PubMed, Scopus, Embase, Web of Science and Cochrane library. Two reviewers independently screened potentially eligible studies according to predefined selection criteria and assessed the risk of bias using a modified version of the Cochrane risk of bias tool. PJI was prespecified as the primary outcome of interest. The meta-analyses were based on risk ratios using random-effects model per default. For the purpose of sensitivity, the corresponding fixed effects model odds ratios were calculated with the use of the Peto method as well. To evaluate a potential difference in effect sizes using different types (subgroups) of antibiotics used in bone cement, and at different follow-up periods, we performed stratified meta-analyses.

Results: Thirty-seven studies were eligible for the systematic review and qualitative synthesis, and 9 trials (6507 total joint arthroplasties) were included in this meta-analysis. Overall ALBC significantly reduced the risk of PJI following primary TJAs (RRs, 0.36; 95% CIs, 0.16 to 0.80; P = 0.01) with a moderate degree of inconsistency (I2 = 47%). Based on stratified meta-analyses the use of gentamicin appeared to have a better effect (P = 0.0005) in the total hip arthroplasty. Pooled data of different antibiotics used in knee arthroplasties showed a significant association of cefuroxime (RRs, 0.08; 95% CIs, 0.01 to 0.63; P = 0.02). Further, ALBCs significantly reduced the PJI at one and two years of follow-up (P = 0.03 and P = 0.005 respectively).

Conclusions: The evidence suggests that ALBCs are effective in reducing the PJI following primary TJA; i.e. between 20 and 84% reduced risk. However, the clear limitations of the available trial evidence highlight the need for joint-specific confirmatory trials, that will need to be designed as cluster-randomized trials of clinics in countries with well-functioning arthroplasty registries.The translational potential of this article: This meta-analysis highlights the prophylactic potential of ALBCs in lowering the risk of infection following primary hip or knee arthroplasties but emphasizes the need for more recent confirmatory trials.

OBJECTIVE: To investigate whether magnetic resonance imaging (MRI) pathologies in the wrist/hand of rheumatoid arthritis (RA) patients are associated with patient-reported outcomes (PROs) at clinical remission and relapse.

METHODS: Wrist/hand MRIs and wrists/hands/feet radiographs were obtained in 114 established RA patients in clinical remission, before tapering their biologic disease-modifying antirheumatic drugs. MRIs were assessed according to the Outcome Measures in Rheumatology (OMERACT) RA MRI score (RAMRIS) for inflammation (synovitis/tenosynovitis/bone marrow edema) and damage (bone erosion/joint space narrowing) at baseline (ie remission) and in case of a relapse (n = 70). Radiographs were assessed according to the Sharp/van der Heijde (SvH) method at baseline. These scores were assessed for associations with health assessment questionnaires (HAQ), visual analog scales (VAS global/pain), EuroQol-5 dimensions and Short-Form 36 physical and mental component summary (SF-36 PCS/MCS) using Spearman correlations, univariate/multivariable linear regression analyses and generalized estimating equations. Furthermore, MRI pathologies were assessed for association with specific hand-related HAQ items using Jonckheere trend tests.

RESULTS: Magnetic resonance imaging-assessed damage was associated with impaired HAQ and SF-36 PCS at remission and relapse (P < .01), independent of clinical and radiographic measures, and was also associated with most of the hand-related HAQ items (P < .03). In multivariate models including MRI, SvH scores were not associated with PROs. MRI-assessed inflammation was not associated with PROs at remission or relapse.

CONCLUSION: Magnetic resonance imaging-assessed wrist/hand damage, but not inflammation, in patients with established RA is associated with patient-reported physical impairment at remission and relapse. The amount of damage in the wrist/hand is associated with reduced hand function.

OBJECTIVE: The elderly, a population defined by an age of ≥65 years, are underrepresented in rheumatology trials, possibly due to investigators' concerns of increased premature discontinuations in higher age groups. The present study was undertaken to evaluate whether the proportion of included elderly individuals (PE) is independently associated with participant retention in rheumatology trials.

METHODS: Medline was searched for randomized controlled trials (RCTs) in rheumatoid arthritis (RA) and osteoarthritis (OA) of any intervention (years 2016 and 2017). PE was either extracted from the research manuscript or estimated from an assumed (truncated) normal distribution. We used mixed-effects meta-regression models including several covariates to assess whether there is an independent association between PE and participant retention. Using sensitivity analyses, we evaluated whether associations were connected to attrition due to lack of efficacy (LoE) or adverse events (AE).

RESULTS: In total, 243 RCTs comprising >48,000 participants were included. Pooled participant retention was 88%. PE was not associated with retention in the unadjusted (P = 0.97) or adjusted (all: P ≥ 0.14) models. Of all covariates, only study duration and type of intervention were associated with retention (both: P < 0.001). Post hoc analyses allowing for interaction revealed a small but statistically significant positive association between PE and retention in pharmacologic interventions and a negative association in physical/physiotherapeutic interventions (overall P for interaction = 0.05). No associations were found for PE and attrition due to LoE or AE.

CONCLUSION: Participant retention in RA and OA trials is high and not associated with PE. These findings should motivate investigators to include more elderly participants in rheumatology trials.