Goal Attainment Scaling as an Outcome Measure for Randomised Controlled Trials: A Systematic Scoping Review
Abstract BACKGROUND: Goal Attainment Scaling (GAS) is an individualised outcome measure which can be used in research settings to assess achievement of participant-important priorities and goals. METHODS: A systematic scoping review was completed with the objective of: (1) Identifying the healthcare settings in which GAS has been used as an outcome measure. (2) Describing how GAS has been implemented by researchers in those trials. PubMed, CENTRAL, EMBASE and PsycINFO were searched without limits from their inceptions to 1 September 2021 for randomised controlled trials conducted in healthcare settings where GAS was used as an outcome measure for adults. Two reviewers independently completed both the screening and data extraction, with a third adjudicating conflicts. RESULTS: Of 1,764 articles screened, 37 studies were included. Most trials (86%) were solely undertaken in outpatient settings. They were frequently conducted within the disciplines of rehabilitation (57%), geriatric medicine (24%) and neurology (11%). Sample sizes ranged from 8 to 468, with a mean of 84 participants. GAS was a primary outcome measure in 38% of studies. There were inconsistencies between trials in the use of scales and the calculation of GAS scores. Implementation aspects such as the personnel involved, the training provided, and calibration and review mechanisms, were heterogeneously and scarcely reported. CONCLUSIONS: GAS has been used as an outcome measure across a wide range of disciplines and trial settings. However, there are inconsistencies in how it has been applied and implemented. Developing a cross-disciplinary practical guide to support a degree of standardisation in its implementation may be beneficial in increasing the reliability and comparability of trial results.