Objective To investigate the agreement between direct and indirect comparisons of competing healthcare interventions.Design Meta-epidemiological study based on sample of meta-analyses of randomised controlled trials. Data sources Cochrane Database of Systematic Reviews and PubMed.Inclusion criteria Systematic reviews that provided sufficient data for both direct comparison and independent indirect comparisons of two interventions on the basis of a common comparator and in which the odds ratio could be used as the outcome statistic.Main outcome measure Inconsistency measured by the difference in the log odds ratio between the direct and indirect methods. ResultsThe study included 112 independent trial networks (including 1552 trials with 478 775 patients in total) that allowed both direct and indirect comparison of two interventions. Indirect comparison had already been explicitly done in only 13 of the 85 Cochrane reviews included. The inconsistency between the direct and indirect comparison was statistically significant in 16 cases (14%, 95% confidence interval 9% to 22%). The statistically significant inconsistency was associated with fewer trials, subjectively assessed outcomes, and statistically significant effects of treatment in either direct or indirect comparisons. Owing to considerable inconsistency, many (14/39) of the statistically significant effects by direct comparison became non-significant when the direct and indirect estimates were combined. ConclusionsSignificant inconsistency between direct and indirect comparisons may be more prevalent than previously observed. Direct and indirect estimates should be combined in mixed treatment comparisons only after adequate assessment of the consistency of the evidence. IntroductionRandomised controlled trials to compare competing interventions are often lacking, and this situation is unlikely to improve in the future because of the inevitable tension between the high cost of clinical trials and the continuing introduction of new treatments.1 2 The dearth of evidence from head to head randomised controlled trials has led to increased use of indirect comparison methods to estimate the comparative effects of treatment. [1][2][3][4] Indirect comparison of competing interventions can be generally defined as a comparison of different treatments for a clinical indication by using data from separate randomised controlled trials, in contrast to direct comparison within randomised controlled trials. Indirect comparison based on a common comparator can preserve certain strengths of randomised allocation of patients for estimating comparative effects of treatment.1 5 6 The term "adjusted indirect comparison" is used to refer to this indirect comparison based on a common intervention (fig 1). 7 Mixed treatment comparison (also known RESEARCHas network meta-analysis or multiple treatment meta-analysis) is a more complex method that combines both indirect and direct estimates simultaneously. [8][9][10] The validity of indirect and mixed treatment comparisons dep...

CT colonography has been used to detect colonic polyps and cancers, but its effect in practice will also be influenced by the frequency with which extracolonic lesions of various types are detected. We performed a systematic review of the types of incidental lesions found on CT colonography. This is necessary to model the benefits and harms of detecting extracolonic lesions. Primary clinical studies of extracolonic findings on CT colonography were identified from electronic databases, scanning reference lists and hand searches of relevant journals and conference proceedings. A data collection proforma was used to collect information on extracolonic findings. 17 discreet studies were identified, involving 3488 patients. In total 40% of patients were recorded to have abnormalities and many had more than one abnormality. Nearly 14% of patients had further investigations and 0.8% were given immediate treatment. Extracolonic cancers were detected in 2.7% (0.9% had N0M0 cancers) and 0.9% had an aortic aneurysm. The number of extracolonic findings was high in all studies. While only a small population were judged "important", the prevalence of serious lesions outside the colon was nevertheless higher than in many other screening programs.

women is as common as asthma and chronic back pain, 1,2 is one of the most difficult and perplexing of women's health problems, and has a multifactorial etiology. 3 Chronic pelvic pain has a major effect on health-related quality of life, work attendance and productivity, 4 and health care use, accounting for 40% of referrals for diagnostic laparoscopy, 5 and is an important contributor to health care expenditures. 6 Treatments for chronic pelvic pain are often unsatisfactory. 7 As part of the evaluation and management phase, patients often undergo diagnostic laparoscopy 8 but actionable pathology is found only occasionally. 9,10 Negative findings at laparoscopy and during follow-up with ultrasound may provide re

CT colonography (CTC) is increasingly used to detect colonic polyps and cancers, but its impact in practice is also influenced by frequent detection of extracolonic lesions. We have previously documented the frequency and nature of such lesions. The current study was performed to assess the clinical resources and costs associated with the investigation and treatment of extracolonic lesions. We reviewed the reports of 225 consecutive CTC examinations carried out on patients with symptoms of bowel cancer. 116 of the 225 were reported to have one or more extracolonic findings. All 116 patients with an abnormality were followed up for 12-24 months. 24 patients underwent further actions (outpatient attendance, investigations, or surgical procedures) as a result of previously undiagnosed lesions unrelated to bowel cancer. The costs of these further actions were derived from the NHS Reference Costs manual 2004. The total cost for further investigations and interventions was 34,329 pounds sterling and the mean cost over the sample of 225 patients was 153 pounds sterling--more than the cost of the CTC itself. The costs were mainly generated by surgical procedures. Resources consumed as a result of extracolonic findings approximately doubled the costs of diagnostic CTC. These costs, along with inconvenience, anxiety, morbidity and occasionally even mortality suffered by patients, must be offset by the good done to some of those with sub-clinical but potentially lethal diseases.