Relationship between patient-reported outcomes of elective surgery and hospital and consultant volume

Our aim was to analyze the relationship for 3 elective operations between outcome [patient-reported outcome measures (PROMs) for functional status, health-related quality of life, and postoperative complications] and both hospital and consultant volume.

Hospitals (NHS and independent) and consultants undertaking at least 10 NHS-funded procedures during 2011/2012 were included (230 hospitals for hip and knee replacement, 257 for hernia repair; 978 consultants for hip replacement, 1172 for knee replacement, and 1288 for hernia repair). Outcomes (disease-specific and generic PROMs, patient-reported complications) were available from the NHS National PROMs Programme for 2009/2010 to 2011/2012. Relationship between case-mix adjusted outcomes and volume investigated using multilevel modeling.

There was considerable variation in hospital volumes (about 10-fold) and consultant volumes (about 5-fold). No significant association was observed between hospital volume and outcome for all 3 procedures. For consultant volume, there was no significant association for knee replacement or hernia repair. However, outcomes were statistically significantly better for hip replacement, although the effect was of little clinical significance: an additional 10 cases was associated with a higher Oxford Hip Score (0.06), higher EQ-5D score (0.001), and lower odds ratio of complications (0.992).

There are unlikely to be any benefits to patients from centralization of elective surgery into higher volume hospitals as regards the effectiveness of surgery or the avoidance of minor complications. There is some evidence that very low volume consultants achieve poorer outcomes than higher volume colleagues but the difference is slight and of little or no clinical significance.