Assessment of publication bias, selection bias, and unavailable data in meta-analyses using individual participant data: a database survey

Assessment of publication bias, selection bias, and unavailable data in meta-analyses using individual participant data: a database survey | BMJ.

 

This article is available freely via Open Access. Please click on the above link to view it fully.

Abstract

Objective To examine the potential for publication bias, data availability bias, and reviewer selection bias in recently published meta-analyses that use individual participant data and to investigate whether authors of such meta-analyses seemed aware of these issues.

Design In a database of 383 meta-analyses of individual participant data that were published between 1991 and March 2009, we surveyed the 31 most recent meta-analyses of randomised trials that examined whether an intervention was effective. Identification of relevant articles and data extraction was undertaken by one author and checked by another.

Results Only nine (29%) of the 31 meta-analyses included individual participant data from “grey literature” (such as unpublished studies) in their primary meta-analysis, and the potential for publication bias was discussed or investigated in just 10 (32%). Sixteen (52%) of the 31 meta-analyses did not obtain all the individual participant data requested, yet five of these (31%) did not mention this as a potential limitation, and only six (38%) examined how trials without individual participant data might affect the conclusions. In nine (29%) of the meta-analyses reviewer selection bias was a potential issue, as the identification of relevant trials was either not stated or based on a more selective, non-systematic approach. Investigation of four meta-analyses containing data from ≥10 trials revealed one with an asymmetric funnel plot consistent with publication bias, and the inclusion of studies without individual participant data revealed additional heterogeneity between trials.

Conclusions Publication, availability, and selection biases are a potential concern for meta-analyses of individual participant data, but many reviewers neglect to examine or discuss them. These issues warn against uncritically viewing any meta-analysis that uses individual participant data as the most reliable. Reviewers should seek individual participant data from all studies identified by a systematic review; include, where possible, aggregate data from any studies lacking individual participant data to consider their potential impact; and investigate funnel plot asymmetry in line with recent guidelines.

Nursing standards: PM aims to tackle ‘care problem’

Nurses will be told to do regular ward rounds and patients encouraged to carry out inspections as part of a drive to improve hospital standards in England

via BBC News – Nursing standards: PM aims to tackle ‘care problem’.

Promoting advance planning for health care and research among older adults: a randomized controlled trial

BMC Medical Ethics | Abstract | Promoting advance planning for health care and research among older adults: a randomized controlled trial.

Abstract (provisional)

Background

Family members are often required to act as substitute decision-makers when health care or research participation decisions must be made for an incapacitated relative. Yet most families are unable to accurately predict older adult preferences regarding future health care and willingness to engage in research studies. Discussion and documentation of preferences could improve proxies’ abilities to decide for their loved ones. This trial assesses the efficacy of an advance planning intervention in improving the accuracy of substitute decision-making and increasing the frequency of documented preferences for health care and research. It also investigates the financial impact on the healthcare system of improving substitute decision-making.

Methods

Dyads (n=240) comprising an older adult and his/her self-selected proxy are randomly allocated to the experimental or control group, after stratification for type of designated proxy and self-report of prior documentation of healthcare preferences. At baseline, clinical and research vignettes are used to elicit older adult preferences and assess the ability of their proxy to predict those preferences. Responses are elicited under four health states, ranging from the subject’s current health state to severe dementia. For each state, we estimated the public costs of the healthcare services that would typically be provided to a patient under these scenarios. Experimental dyads are visited at home, twice, by a specially trained facilitator who communicates the dyad-specific results of the concordance assessment, helps older adults convey their wishes to their proxies, and offers assistance in completing a guide entitled My Preferences that we designed specifically for that purpose. In between these meetings, experimental dyads attend a group information session about My Preferences. Control dyads attend three monthly workshops aimed at promoting healthy behaviors. Concordance assessments are repeated at the end of the intervention and 6 months later to assess improvement in predictive accuracy and cost savings, if any. Copies of completed guides are made at the time of these assessments.

Discussion

This study will determine whether the tested intervention guides proxies in making decisions that concur with those of older adults, motivates the latter to record their wishes in writing, and yields savings for the healthcare system. Trial Registration: ISRCTN89993391

Men ‘most unhappy about beer bellies’

Four out of five men confess to being unhappy about their body, suggests an online survey by the University of the West of England.

via BBC News – Body image: Men ‘most unhappy about beer bellies’.

Timing of onset of cognitive decline: results from Whitehall II prospective cohort study

Timing of onset of cognitive decline: results from Whitehall II prospective cohort study | BMJ.

This article is available freely via Open Access. Please click on the above link to view it fully.

 

Abstract

Objectives To estimate 10 year decline in cognitive function from longitudinal data in a middle aged cohort and to examine whether age cohorts can be compared with cross sectional data to infer the effect of age on cognitive decline.

Design Prospective cohort study. At study inception in 1985-8, there were 10 308 participants, representing a recruitment rate of 73%.

Setting Civil service departments in London, United Kingdom.

Participants 5198 men and 2192 women, aged 45-70 at the beginning of cognitive testing in 1997-9.

Main outcome measure Tests of memory, reasoning, vocabulary, and phonemic and semantic fluency, assessed three times over 10 years.

Results All cognitive scores, except vocabulary, declined in all five age categories (age 45-49, 50-54, 55-59, 60-64, and 65-70 at baseline), with evidence of faster decline in older people. In men, the 10 year decline, shown as change/range of test×100, in reasoning was −3.6% (95% confidence interval −4.1% to −3.0%) in those aged 45-49 at baseline and −9.6% (−10.6% to −8.6%) in those aged 65-70. In women, the corresponding decline was −3.6% (−4.6% to −2.7%) and −7.4% (−9.1% to −5.7%). Comparisons of longitudinal and cross sectional effects of age suggest that the latter overestimate decline in women because of cohort differences in education. For example, in women aged 45-49 the longitudinal analysis showed reasoning to have declined by −3.6% (−4.5% to −2.8%) but the cross sectional effects suggested a decline of −11.4% (−14.0% to −8.9%).

Conclusions Cognitive decline is already evident in middle age (age 45-49).

Unite rejects pensions deal

via Unite rejects pensions deal | News | Health Service Journal.

This article is solely the work of the HSJ. For a full copy of the article please contact the library.

union representing more than 100,000 NHS workers has rejected the government’s offer on pensions, opening up the possibility for more industrial action.

 

Impact of document type on reporting quality of clinical drug trials: a comparison of registry reports, clinical study reports, and journal publications | BMJ

Impact of document type on reporting quality of clinical drug trials: a comparison of registry reports, clinical study reports, and journal publications | BMJ.

This article is available freely via Open Access. Please click on the above link to view it fully.

 

Abstract

Objective To investigate to what extent three types of documents for reporting clinical trials provide sufficient information for trial evaluation.

Design Retrospective analysis

Data sources Primary studies and corresponding documents (registry reports, clinical study reports, journal publications) from 16 health technology assessments of drugs conducted by the German Institute for Quality and Efficiency in Health Care between 2006 and February 2011.

Data analysis We assessed reporting quality for each study and each available document for six items on methods and six on outcomes, and dichotomised them as “completely reported” or “incompletely reported.” For each document type, we calculated the proportion of studies with complete reporting for methods and outcomes, per item and overall, and compared the findings.

Results We identified 268 studies. Publications, study reports and registry reports were available for 192 (72%), 101 (38%), and 78 (29%) studies, respectively. Reporting quality was highest in study reports, which overall provided complete information for 90% of items (1086/1212). Registry reports provided more complete information on outcomes than on methods (overall 330/468 (71%) v 147/468 (31%)); the same applied to publications (594/1152 (52%) v 458/1152 (40%)). In the matched pairs analysis, reporting quality was poorer in registry reports than in study reports for overall methods and outcomes (P<0.001 in each case). Compared with publications, reporting quality was poorer in registry reports for overall methods (P<0.001), but better for outcomes (P=0.005).

Conclusion Registry reports and publications insufficiently report clinical trials but may supplement each other. Measures to improve reporting include the mandatory worldwide implementation of adequate standards for results registration

Let doctors help terminally ill patients to die, says commission

via Let doctors help terminally ill patients to die, says commission | BMJ.

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Doctors in England and Wales could be allowed to assist terminally ill people to end their lives under strict safeguards without endangering the vulnerable, the most comprehensive UK inquiry into assisted dying has concluded.

 

DH leak reveals uncertainty over 11,000 PCT jobs | News | Health Service Journal

Exclusive: DH leak reveals uncertainty over 11,000 PCT jobs | News | Health Service Journal.

This article is solely the work of the HSJ. For a full copy of the article please contact the library.

A leaked Department of Health document shows for the first time where commissioning staff are likely to move in the restructured NHS – however it also reveals that a lack of clarity remains over thousands of jobs

Whooping cough cases increase in England and Wales

Cases of whooping cough in England and Wales have more than doubled in the past year, says the Health Protection Agency.

via BBC News – Whooping cough cases increase in England and Wales.