Bariatric treatments for adult obesity - Institute of Health Economics

Data extractionData extracted from studies include study design, objective, perspective, timelines, bariatricinterventions under investigation, country, health and cost outcomes, results from marginal analysis,and study conclusions.Quality assessment criteriaAn informal quality assessment of economic studies was conducted using criteria adapted fromDrummond et al. 2 and Drummond et al. 3 The purpose of providing a quality assessment ofeconomic studies in this report is to identify the components included in the studies and to providea general assessment of the quality of the economic studies reviewed. The quality of potentiallyrelevant studies was assessed by one reviewer.Secondary analysis of Provincial Health Utilization databasesSource of informationInformation on costs and resource utilization were retrieved from three provincial health utilizationdatabases between 2004 and 2008 fiscal years. The Alberta Physician Claims Database (PCD)provided information related to billing services to physicians for medically insured services inAlberta. The Alberta Discharge Abstracts Database (DAD) provided information related to hospitalinpatient procedures. The Ambulatory Care Classification System (ACCS) provided informationrelated to outpatient procedures. Note that cost data in the DAD and ACCS include patient-specificdrug and supply costs, functional centre direct costs such as salaries (excluding physician services),medical and surgical supplies, and functional center indirect costs such as administration andsupport services (Alberta Case Cost Report, Alberta Health and Wellness, December 2009).AnalysisThe analysis consisted of two components. The first was an estimate of the direct health servicecosts of bariatric surgery. Patients who received bariatric surgery in 2005–2006 were identified usingthe Canadian Classification of Health Interventions (CCI) codes (see below) that corresponded tobariatric surgery. Total physician and inpatient costs for each patient with a corresponding CCI codewere calculated by aggregating all costs of physician and inpatient services provided within the datesof admission and discharge. A mean cost per bariatric surgery was then calculated by divided thetotal cost of bariatric surgery across all patients by the number of patients in the cohort.The second component was a pre-post analysis comparing the health service utilization before andafter surgery. For the cohort of patients who received bariatric surgery in 2005–2006, total physician,inpatient, and outpatient visits and costs were calculated across all patients, over a period of 2 yearsbefore and 2 years after surgery. Total physician, inpatient, and outpatient visits and costs weredivided by the number of patients in the cohort to provide a mean visit and a cost per patient. Themean visit and costs before and after surgery were then compared to each other. Note that all costswere adjusted to reflect 2006 dollars using the Alberta Consumer Price Index (CPI). Furthermore,visits or costs that were greater than three times its standard deviation in each year were censoredfrom the analysis.Bariatric treatments for adult obesity 161