Core Outcome Measures in Effectiveness Trials

The patient perspective of outcomes of bariatric surgery: The need for a ’core’ set of patient-reported outcomes.

General Information

Background: Patient-reported outcomes (PROs) are central to evaluating bariatric surgery. However there is a lack of consistency as to which outcomes to measure. A core outcome set, which is a minimum set of outcomes that should be reported on in every study of a particular disease/condition, is needed to improve the consistency of PROs measured in bariatric surgery. This research aims to evaluate outcomes of importance to patients and to use this information to develop a core set of PROs.

Methods: Systematic reviews of the literature reporting PROs and patient experiences in bariatric surgery have been undertaken to build a list of PRO measures and identify themes relating to patient experiences of bariatric surgery.

Results: 3874 abstracts were screened and 86 studies included. 68 different validated PRO measures were used, representing 330 different PROs. These were grouped into 21 health domains. The psychological/emotional domain was the most commonly measured domain (129 outcomes), followed by the physical domain (33 outcomes). The qualitative literature identified 21 studies with another 36 themes. While some of these themes overlap with the health domains from the PRO studies, they also provide some new insights on the impact of surgery that are not represented in the PRO studies (e.g. the development of new addictions to fill the void of food).

Conclusions and further work: Patient-reported outcomes, measured using validated questionnaires provide a means of measuring the effect of surgery over time. However, qualitative studies can shed light on the detail and complexity of experiences that quantitative measures cannot always reach. Both approaches are needed to develop a core outcome set that truly reflects patient experiences. Qualitative interviews with more patients will explore whether published PROs reflect outcomes patients themselves consider important. Data from the interviews will supplement the list of outcomes identified in the literature and will be used to inform a survey. The survey will ask patients to prioritise PROs using Delphi methods to reduce the list before a final core set of PROs will be agreed in a consensus meeting with a sample of patients.

To evaluate outcomes of importance to patients and to use this information to develop a core set of PROs.

Karen Coulman, Amanda Owen-Smith, Rob Andrews, Sally Norton, Richard Welbourn, Jane Blazeby


British Journal of Surgery
2 - 3
Further Study Information

Funding source(s):

Health Area

Disease Category
Endocrine & metabolic

Disease Name

Target Population

Age Range
18 - 100


Nature / type of Intervention


Systematic review

Stakeholders Involved

Study investigators

Study Type

Patient perspectives
Systematic review of outcomes measured in trials
Systematic review of qualitative research

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