Short email with attachment versus long email without attachment when contacting authors to request unpublished data for a systematic review: a nested randomised trial

ObjectiveSystematic reviews often rely on the acquisition of unpublished analyses or data. We carried out a nested randomised trial comparing two different approaches for contacting authors to request additional data for a systematic review.ParticipantsParticipants were authors of published reports of prevention or treatment trials in stroke in which there was central adjudication of events. A primary and secondary research active author were selected as contacts for each trial.InterventionsAuthors were randomised to be sent either a short email with a protocol of the systematic review attached (‘Short’) or a longer email that contained detailed information and without the protocol attached (‘Long’). A maximum of two emails were sent to each author to obtain a response. The unit of analysis was trial, accounting for clustering by author.Primary and secondary outcome measuresThe primary outcome was whether a response was received from authors. Secondary outcomes included time to response, number of reminders needed before a response was received and whether authors agreed to collaborate.Results88 trials with 76 primary authors were identified in the systematic review, and of these, 36 authors were randomised to Short (trials=45) and 40 to Long (trials=43). Responses were received for 69 trials. There was no evidence of a difference in response rate between trial arms (Short vs Long, OR 1.10, 95% CI 0.36 to 3.33). There was no evidence of a difference in time to response between trial arms (Short vs Long, HR 0.91, 95% CI 0.55 to 1.51). In total, 27% of authors responded within a day and 22% of authors never responded.ConclusionsThere was no evidence to suggest that email format had an impact on the number of responses received when acquiring data for a systematic review involving stroke trials or the time taken to receive these responses.

PP29 Evaluating Supplementary Search Methods: Outcomes To Measure And Why

Introduction:In a recently published review of supplementary search methods, we proposed that researchers could usefully record time taken to search and present outcome values in similar way to existing studies, to facilitate generalisability of outcomes, where appropriate. We also discuss the idea of linking literature search effectiveness to study value. In this vignette, we discuss which outcomes we believe are important to measure and why. We discuss this in the context of the review of supplementary search methods and using a recently submitted evaluation of contacting study authors for context.Methods:In a recently completed systematic review, we contacted eighty-two study authors to ask three questions. We aimed to measure the following outcomes when contacting study authors: Effectiveness - determined as number of contacts compared to number of replies; Efficiency - i) time to make contact and ii) time between contact and reply. We determined this in hours, minutes and seconds, in line with other studies; Cost - determined by comparing the efficiency of contacting authors with the effectiveness; and Value - determined by reading and comparing the published studies with the replies received to see if any unique data were identified.Results:Effectiveness: thirty-eight answers were received from eighty-two possible contacts. Efficiency: In total, author contact took six hours, fifty-four minutes and twenty-five seconds across thirty-nine weeks. Replies were received across zero to thirty-nine days (median fourteen days). Cost: Cost for staff time was GBP 80.33 (EUR 91.20) or GBP 2.11 (EUR 2.40) per e-mail reply received. Value: We were able to identify value in author replies for each of the questions asked.Conclusions:In a recently published review of supplementary search methods, and a linked evaluation of the effectiveness of contacting study authors, we suggest outcomes that should be measured to determine effectiveness of literature search methods. We conclude that measuring these outcomes demonstrate both effectiveness and value.

Externalizing biases and hallucinations in source-monitoring, self-monitoring and signal detection studies: a meta-analytic review

BackgroundCognitive models have postulated that auditory hallucinations arise from the misattribution of internally generated cognitive events to external sources. Several experimental paradigms have been developed to assess this externalizing bias in clinical and non-clinical hallucination-prone samples, including source-monitoring, verbal self-monitoring and auditory signal detection tasks. This meta-analysis aims to synthesize the wealth of empirical findings from these experimental studies.MethodA database search was carried out for reports between January 1985 and March 2012. Additional studies were retrieved by contacting authors and screening references of eligible reports. Studies were considered eligible if they compared either (i) hallucinating and non-hallucinating patients with comparable diagnoses, or (ii) non-clinical hallucination-prone and non-prone participants using source-monitoring, verbal self-monitoring or signal detection tasks, or used correlational analyses to estimate comparable effects.ResultsThe analysis included 15 clinical (240 hallucinating patients and 249 non-hallucinating patients) and nine non-clinical studies (171 hallucination-prone and 177 non-prone participants; 57 participants in a correlation study). Moderate-to-large summary effects were observed in both the clinical and analogue samples. Robust and significant effects were observed in source-monitoring and signal detection studies, but not in self-monitoring studies, possibly due to the small numbers of eligible studies in this subgroup. The use of emotionally valenced stimuli led to effects of similar magnitude to the use of neutral stimuli.ConclusionsThe findings suggest that externalizing biases are important cognitive underpinnings of hallucinatory experiences. Clinical interventions targeting these biases should be explored as possible treatments for clients with distressing voices.

An Evaluation of Systematic Reviews of Palliative Care Services

This review aimed to identify and appraise all systematic reviews of palliative care services, to examine their findings in relation to methods used, and to explore whether further methods such as meta-analysis and meta-regression may be worthwhile. Ten databases were searched and augmented by hand searching specific journals, contacting authors, and examining the reference lists of all papers retrieved. Five systematic reviews met the inclusion criteria, and the update electronic search identified a further systematic review which found similar studies. A total of 39 studies were identified by the five systematic reviews. Of the 39 studies, 15 were RCTS, and 12 of those were North American. In comparison, the majority of U.K. studies were retrospective. Each review concluded similarly that there was a lack of good quality evidence on which to base conclusions. The more recent reviews were more rigorous, but none used a quantitative analysis. Despite the difficulties in combining heterogeneous interventions and outcomes in meta-analysis or meta-regression, such techniques may be valuable. More high quality evidence is needed to compare the relative merits of the differences in models of palliative care services, so that countries can learn from other appropriate systems of care at end of life.