Objectives To assess the methodological quality of intention to treat analysis as reported in randomised controlled trials in four large medical journals.

Brief interventions consistently produced reductions in alcohol consumption. When data were available by gender, the effect was clear in men at one year of follow up, but unproven in women. Longer duration of counselling probably has little additional effect. The lack of differences in outcomes between efficacy and effectiveness trials suggests that the current literature had clear relevance to routine primary care. Future trials should focus on women and on delineating the most effective components of interventions.

Patients with elevated blood pressure should follow a weight-reducing diet, take regular exercise, and restrict alcohol and salt intake. Available evidence does not support relaxation therapies, calcium, magnesium or potassium supplements to reduce blood pressure.

We found moderate-quality evidence that brief interventions can reduce alcohol consumption in hazardous and harmful drinkers compared to minimal or no intervention. Longer counselling duration probably has little additional effect. Future studies should focus on identifying the components of interventions which are most closely associated with effectiveness.

Brief interventions can reduce alcohol consumption in men, with benefit at a year after intervention, but they are unproven in women for whom there is insufficient research data. Longer counselling has little additional effect over brief intervention. The lack of differences in outcomes between efficacy and effectiveness trials suggests that the current literature is relevant to routine primary care.

Transition of care for adolescents from paediatric services to adult health services. Cochrane Database of Systematic Reviews, (4), [CD009794].

BackgroundSystematic review methodologies can be harnessed to help researchers to understand and explain how complex interventions may work. Typically, when reviewing complex interventions, a review team will seek to understand the theories that underpin an intervention and the specific context for that intervention. A single published report from a research project does not typically contain this required level of detail. A review team may find it more useful to examine a “study cluster”; a group of related papers that explore and explain various features of a single project and thus supply necessary detail relating to theory and/or context.We sought to conduct a preliminary investigation, from a single case study review, of techniques required to identify a cluster of related research reports, to document the yield from such methods, and to outline a systematic methodology for cluster searching.MethodsIn a systematic review of community engagement we identified a relevant project – the Gay Men’s Task Force. From a single “key pearl citation” we conducted a series of related searches to find contextually or theoretically proximate documents. We followed up Citations, traced Lead authors, identified Unpublished materials, searched Google Scholar, tracked Theories, undertook ancestry searching for Early examples and followed up Related projects (embodied in the CLUSTER mnemonic).ResultsOur structured, formalised procedure for cluster searching identified useful reports that are not typically identified from topic-based searches on bibliographic databases. Items previously rejected by an initial sift were subsequently found to inform our understanding of underpinning theory (for example Diffusion of Innovations Theory), context or both. Relevant material included book chapters, a Web-based process evaluation, and peer reviewed reports of projects sharing a common ancestry. We used these reports to understand the context for the intervention and to explore explanations for its relative lack of success. Additional data helped us to challenge simplistic assumptions on the homogeneity of the target population.ConclusionsA single case study suggests the potential utility of cluster searching, particularly for reviews that depend on an understanding of context, e.g. realist synthesis. The methodology is transparent, explicit and reproducible. There is no reason to believe that cluster searching is not generalizable to other review topics. Further research should examine the contribution of the methodology beyond improved yield, to the final synthesis and interpretation, possibly by utilizing qualitative sensitivity analysis.

BackgroundIt is estimated that only 39% of men and 29% of women in England achieve the levels of physical activity that are recommended to protect health and prevent disease. One approach to addressing this problem has been the development of exercise referral schemes (ERSs), in which health professionals refer patients to external exercise providers. These schemes have been widely rolled out across the UK despite concerns that they may not produce sustained changes in levels of physical activity and, therefore, may not be cost-effective interventions. The evidence to determine clinical effectiveness and cost-effectiveness was evaluated in 2009. This review seeks to update this earlier work by incorporating new evidence and re-examining the cost-effectiveness.ObjectivesTo assess the clinical effectiveness and cost-effectiveness of ERSs compared with usual care.DesignExhaustive searches of relevant electronic databases and journals were undertaken to identify new studies evaluating ERSs using a randomised controlled trial (RCT) design. RCTs that incorporated a qualitative evaluation of the intervention were identified in order to explore the barriers and facilitators to the uptake of and adherence to ERSs. Data were extracted using a previously designed tool and study quality assessed for potential bias. Where data could be pooled, meta-analyses were carried out. Qualitative analysis was also undertaken using a thematic approach. The cost-effectiveness was evaluated using a Markov structure which estimated the likelihood of becoming physically active and the subsequent risk reduction on coronary heart disease (CHD), stroke and type 2 diabetes mellitus. The model adopts a lifetime horizon, and a NHS and Personal Social Services perspective was taken with discounting at 1.5% for both costs and benefits.ResultsThe search identified one new RCT and one new qualitative study. The new data were pooled with existing data from the 2011 review by Paveyet al.[Pavey TG, Anokye N, Taylor AH, Trueman P, Moxham T, Fox KR,et al.The clinical effectiveness and cost-effectiveness of exercise referral schemes: a systematic review and economic evaluation.Health Technol Assess2011;15(44)] to give a total of eight studies with 5190 participants. The proportion of individuals achieving 90–150 minutes of at least moderate-intensity activity per week at 6–12 months’ follow-up was greater for ERSs than usual care (relative risk 1.12; 95% confidence interval 1.04 to 1.20). Older patients and those referred for CHD risk factors appeared to be more likely than others to increase their levels of physical activity. Qualitative evidence suggests that interventions enabling the development of social support networks are beneficial in promoting uptake and adherence. Exercise referral gained 0.003 quality-adjusted life-years (QALYs) at an additional cost of £225 per person. The estimated mean incremental cost-effectiveness ratio (ICER) in the probabilistic sensitivity analysis was £76,276. In the univariate sensitivity analysis the results were very sensitive (ICERs ranged from < £30,000 to > £100,000) to changes in the effect of ERSs on physical activity uptake and the duration of the protective effects and the direct health-related quality-of-life gains attributable to physical activity.ConclusionsExercise referral schemes result in a small improvement in the number of people who increase their levels of physical activity. The cost-effectiveness analysis indicates that the ICER for ERSs compared with usual care is around £76,000 per QALY, although the cost-effectiveness of ERSs is subject to considerable uncertainty.Study registrationThis study is registered as PROSPERO CRD42013005200.FundingNational Institute for Health Research Health Technology Assessment programme.