A systematic methodological review of non-randomised interventional studies of elective ventral hernia repair: clear definitions and a standardised minimum dataset are needed

S G Parker,C P J Wood,A C J Windsor,A A O Plumb,M Erotocritou,S Mallett,S Halligan,R W Boulton

doi:10.1007/s10029-019-01979-9

S G Parker, C P J Wood + Show 6 more

Open Access

https://doi.org/10.1007/s10029-019-01979-9

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Abstract

BackgroundVentral hernias (VHs) often recur after surgical repair and subsequent attempts at repair are especially challenging. Rigorous research to reduce recurrence is required but such studies must be well-designed and report representative and comprehensive outcomes.ObjectiveWe aimed to assesses methodological quality of non-randomised interventional studies of VH repair by systematic review.MethodsWe searched the indexed literature for non-randomised studies of interventions for VH repair, January 1995 to December 2017 inclusive. Each prospective study was coupled with a corresponding retrospective study using pre-specified criteria to provide matched, comparable groups. We applied a bespoke methodological tool for hernia trials by combining relevant items from existing published tools. Study introduction and rationale, design, participant inclusion criteria, reported outcomes, and statistical methods were assessed.ResultsFifty studies (17,608 patients) were identified: 25 prospective and 25 retrospective. Overall, prospective studies scored marginally higher than retrospective studies for methodological quality, median score 17 (IQR: 14–18) versus 15 (IQR 12–18), respectively. For the sub-categories investigated, prospective studies achieved higher median scores for their, ‘introduction’, ‘study design’ and ‘participants’. Surprisingly, no study stated that a protocol had been written in advance. Only 18 (36%) studies defined a primary outcome, and only 2 studies (4%) described a power calculation. No study referenced a standardised definition for VH recurrence and detection methods for recurrence varied widely. Methodological quality did not improve with publication year or increasing journal impact factor.ConclusionCurrently, non-randomised interventional studies of VH repair are methodologically poor. Clear outcome definitions and a standardised minimum dataset are needed.

Highlights

In the UK, 44,000 ventral hernia (VH) repairs were performed in 2010, increasing to nearly 50,000 in 2015, a 13% rise over 5 years [1]
We have recently investigated the methodological quality of randomised controlled trials (RCTs) of VH repair [8] and found that studies frequently employed poor methods, risking bias
In our first methodological systematic review [8], we found that reported variables in randomised controlled trials (RCTs) of VH were heterogenous and lacked standardisation, concluding that clear outcome definitions and a standardised minimum dataset are needed if VH research is to be clinically useful and methodologically credible

Summary

Introduction

In the UK, 44,000 ventral hernia (VH) repairs were performed in 2010, increasing to nearly 50,000 in 2015, a 13% rise over 5 years [1]. We have recently investigated the methodological quality of randomised controlled trials (RCTs) of VH repair [8] and found that studies frequently employed poor methods, risking bias. There was no standardised definition for hernia recurrence, length of follow-up, or methods to diagnose recurrence This current variation in reported perioperative variables and outcomes frustrates comparison of outcomes across different trials. There is an urgent need to establish a standardised minimum dataset for trials of VH repair Adopting such a dataset would facilitate data pooling and allow researchers to better explore the impact of patient demographics, hernia characteristics, and intra-operative variables on both operative and patient outcomes. Clear outcome definitions and a standardised minimum dataset are needed

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