Understanding of regional variation in the use of surgery

Abstract

The use of common surgical procedures varies widely across regions. Differences in illness burden, diagnostic practices, and patient attitudes about medical intervention explain only a small degree of regional variation in surgery rates. Evidence suggests that surgical variation results mainly from differences in physician beliefs about the indications for surgery, and the extent to which patient preferences are incorporated into treatment decisions. These two components of clinical decision making help to explain the so-called surgical signatures of specific procedures, and why some consistently vary more than others. Variation in clinical decision making is, in turn, affected by broad environmental factors, including technology diffusion, supply of specialists, local training frameworks, financial incentives, and regulatory factors, which vary across countries. Better scientific evidence about the comparative effectiveness of surgical and non-surgical interventions could help to mitigate regional variation, but broader dissemination of shared decision aids will be essential to reduce variation in preference-sensitive disorders.

Figure 1

Variation in rates of major surgery for ten common procedures among 306 hospital referral regions in the US, based on 2008–10 national Medicare data. The extremal ratio reflects the highest rates divided by the lowest. The interquartile ratio is the 75^th percentile rate divided by the 25^th percentile. The systematic component of variation (SCV) represents the true, non-random part of observed variations.^,

Figure 2

Conceptual model of regional variation in the use of surgery.

Figure 3

The association between regional variation in the US and the UK for the specified period (SCV: systematic component of variation; CABG: coronary artery bypass grafting; PCI: percutaneous coronary intervention).