Distance From Bariatric Centres of Excellence Is Not Associated With Higher Postoperative Complication and Readmission Rates

Aristithes G Doumouras, MD, Fady Saleh, MD, MPH, Scott Gmora, MD, Mehran Anvari, MD, Dennis Hong, MD, MSc. McMaster University

Background: The Ontario Bariatric Network services a population of 12.8 million in an area equivalent in size to California, Oregon, Washington and Nevada combined through just 4 bariatric surgery Centers of Excellence (COE). This study investigates whether the COE model impacts complication and readmission rates for patients traveling great distances for bariatric surgery.

Methods: This study identified all patients aged >18 who received bariatric surgery from April 2009 until March 2012. The exposure of interest was distance from patients’ primary residence, approximated using Forward Sortation Areas – which utilizes the first three characters of a patient’s postal code, to the bariatric COE. Outcomes of interest were overall complication rate during a patient’s initial admission or readmission within 30 days of the index procedure and readmission rate within 30 days of the index procedure. Univariable and multivariable logistic regression were used to examine the impact of distance on patient outcomes. Because health resource allocation in Ontario is determined based on geographic Local Health Integration Networks (LHINs), whether a patient resided within a LHIN with a COE (versus not) was also examined with respect to complication and readmission rate.

Results: 5,007 patients were identified for inclusion in this study. 416 (8.3%) patients underwent a sleeve gastrectomy while 4,591 (91.7%) had a gastric bypass. Overall 98.1% had a laparoscopic procedure. The mean distance from patient residence to the COE where bariatric surgery occurred was 117.2 km (SD 168.5) and the majority of patients did not reside within a LHIN with a COE, 3,192 (63.8%). Patients living 100 km or more from COE had a lower complication and readmission rate, 10.4% and 5.0% respectively, compared to 12.3% and 6.6% for those who lived closer; P value 0.055 and 0.025 respectively. Patients living within a LHIN without a COE also had a lower complication (10.7% versus 13.4%) and readmission (5.9% versus 6.5%) rate compared to those who did, P Value 0.003 and 0.429 respectively. After multivariable adjustment for procedure type and important patient characteristics, the odds of a complication for each 10 km increase in distance from a COE was Odds Ratio 1.00 [95% Confidence Interval (CI): 0.99, 1.01; P = 0.986] while the OR of complication for those outside a LHIN with a COE compared to those within was 0.77 (95% CI: 0.63, 0.93; P Value 0.003). With regards to readmission, the OR for every 10 km increase in distance from a COE was 0.99 (95% CI: 0.98, 1.00; P = 0.082) while for those living outside a LHIN with a COE compared to those within was 1.00 (95% CI: 0.77, 1.30; P=0.982).

Conclusion: It appears that the COE model, where a few centers in high population areas service a large geographic region, is adequate in ensuring patients living further away receive appropriate short-term care.