Clustering of continuous and binary outcomes at the general practice level in individually randomised studies in primary care - a review of 10 years of primary care trials

Clinical Observation, Management and Function Of low back pain Relief Therapies (COMFORT): A cluster randomised controlled trial protocol

INTRODUCTION

Low back pain (LBP) is commonly treated with opioid analgesics despite evidence that these medicines provide minimal or no benefit for LBP and have an established profile of harms. International guidelines discourage or urge caution with the use of opioids for back pain; however, doctors and patients lack practical strategies to help them implement the guidelines. This trial will evaluate a multifaceted intervention to support general practitioners (GPs) and their patients with LBP implement the recommendations in the latest opioid prescribing guidelines.

METHODS AND ANALYSIS

This is a cluster randomised controlled trial that will evaluate the effect of educational outreach visits to GPs promoting opioid stewardship alongside non-pharmacological interventions including heat wrap and patient education about the possible harms and benefits of opioids, on GP prescribing of opioids medicines dispensed. At least 40 general practices will be randomised in a 1:1 ratio to either the intervention or control (no outreach visits; GP provides usual care). A total of 410 patient-participants (205 in each arm) who have been prescribed an opioid for LBP will be enrolled via participating general practices. Follow-up of patient-participants will occur over a 1-year period. The primary outcome will be the cumulative dose of opioid dispensed that was prescribed by study GPs over 1 year from the enrolment visit (in morphine milligram equivalent dose). Secondary outcomes include prescription of opioid medicines, benzodiazepines, gabapentinoids, non-steroidal anti-inflammatory drugs by study GPs or any GP, health services utilisation and patient-reported outcomes such as pain, quality of life and adverse events. Analysis will be by intention to treat, with a health economics analysis also planned.

ETHICS AND DISSEMINATION

The trial received ethics approval from The University of Sydney Human Research Ethics Committee (2022/511). The results will be disseminated via publications in journals, media and conference presentations.

TRIAL REGISTRATION NUMBER

ACTRN12622001505796.

Intracluster correlation coefficients from school-based cluster randomized trials of interventions for improving health outcomes in pupils

BACKGROUND AND OBJECTIVES

To summarize intracluster correlation coefficient (ICC) estimates for pupil health outcomes from school-based cluster randomized trials (CRTs) across world regions and describe their relationship with study design characteristics and context.

METHODS

School-based CRTs reporting ICCs for pupil health outcomes were identified through a literature search of MEDLINE (via Ovid). ICC estimates were summarized both overall and for different categories of study characteristics.

RESULTS

Two hundred and forty-six articles reporting ICC estimates were identified. The median (interquartile range) ICC was 0.031 (0.011 to 0.08) at the school level (N = 210) and 0.063 (0.024 to 0.1) at the class level (N = 46). The distribution of ICCs at the school level was well described by the beta and exponential distributions. Besides larger ICCs in definitive trials than feasibility studies, there were no clear associations between study characteristics and ICC estimates.

CONCLUSION

The distribution of school-level ICCs worldwide was similar to previous summaries from studies in the United States. The description of the distribution of ICCs will help to inform sample size calculations and assess their sensitivity when designing future school-based CRTs of health interventions.

Effectiveness and implementation success of a co-produced physical activity referral scheme in Germany: study protocol of a pragmatic cluster randomised trial

Background

While effective physical activity referral schemes (PARSs) and related structures for promoting physical activity (PA) already exist in several countries, in Germany, PARSs have not yet been implemented systematically and nationwide. Through a co-production approach with relevant actors in the German healthcare system, a PARS was developed, and an implementation plan was created (e.g. financing). This study protocol aims to evaluate the developed PARS for people with non-communicable diseases (NCDs) in Germany regarding its potential effectiveness and implementation success.

Methods

To evaluate the effectiveness and implementation success of the PARS, we will apply a pragmatic cluster-randomised controlled trial (cRCT) in Hybrid II design by comparing two intervention groups (PARS vs PA advice [PAA]). The trial will take place in the Nürnberg metropolitan region, with 24 physician practices recruiting 567 people with NCDs. Both groups will receive brief PA advice from a physician to initially increase the participants’ motivation to change their activity level. Subsequently, the PARS group will be given individualised support from an exercise professional to increase their PA levels and be transferred to local exercise opportunities. In contrast, participants in the PAA group will receive only the brief PA advice as well as information and an overview of regional PA offerings to become more active at their own initiative. After 12 and 24 weeks, changes in moderate to vigorous PA and in physical activity-related health competence (movement competence, control competence, self-regulation competence) will be measured as primary outcomes. Secondary outcomes will include changes in quality of life. To measure implementation success, we refer to the RE-AIM framework and draw on patient documentation, interviews, focus groups and surveys of the participating actors (physicians, exercise professionals).

Discussion

Through a between-group comparison, we will investigate whether additional individual support by an exercise professional compared to brief PA advice alone leads to higher PA levels in people with NCDs. The acceptance and feasibility of both interventions in routine care in the German healthcare system will also be evaluated.

Trial registration

ClinicalTrials.gov, NCT04947787. Registered 01 June 2021.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13833-2.

Methodological aspects of a randomized within-patient concurrent controlled design for clinical trials in spine surgery

INTRODUCTION

Randomized controlled trials are considered the highest level of evidence, but their feasibility in the surgical field is severely hampered by methodological and practical issues. Concurrent comparison between the experimental and control conditions within the same patient can be an effective strategy to mitigate some of these challenges and improve generalizability, mainly by the elimination of between-patient variability and reduction of the required sample size. This article aims (1) to describe the methodological aspects of a randomized within-patient controlled trial and (2) to quantify the added value of this design, based on a recently completed randomized within-patient controlled trial on bone grafts in instrumented lumbar posterolateral spinal fusion.

METHODS

Boundary conditions for the application of the randomized within-patient controlled trial design were identified. Between-patient variability was quantified by the intraclass correlation coefficient and concordance in the primary fusion outcome. Sample size, study duration and costs were compared with a classic randomized controlled trial design.

RESULTS

Boundary conditions include the concurrent application of the experimental and control conditions to identical but physically separated sites. Moreover, the outcome of interest should be local, uncorrelated and independently assessable. The spinal fusion outcomes within a patient were found to be more similar than between different patients (intraclass correlation coefficient 32% and concordance 64%), demonstrating a clear effect of patient-related factors. The randomized within-patient controlled trial design allowed a reduction of the sample size to one-third of a parallel-group randomized controlled trial, thereby halving the trial duration and costs.

CONCLUSION

When suitable, the randomized within-patient controlled trial is an efficient design that provides a solution to some of the considerable challenges of a classic randomized controlled trial in (spine) surgery. This design holds specific promise for efficacy studies of non-active bone grafts in instrumented posterolateral fusion surgery.