title: Healthcare costs associated with change in body mass index in patients with type 2 diabetes mellitus in Spain: the ECOBIM study.
abstract: BACKGROUND
  Weight management is considered a key therapeutic strategy in type 2 diabetes mellitus. However, little is known about the impact of weight loss or body mass index (BMI) reduction on type 2 diabetes-related healthcare costs.
  
  
  OBJECTIVE
  The aim of this study was to estimate the economic impact of change in BMI among patients with type 2 diabetes mellitus from the Spanish healthcare system perspective.
  
  
  METHODS
  The ECOBIM study is an observational, non-interventional study in which data on BMI change and costs incurred by patients with type 2 diabetes were collected cross-sectionally and retrospectively for a 12-month period. Generalized linear mixed models were applied to estimate the effects of (i) BMI change in general (one-slope model); (ii) BMI gain and no BMI gain (two-slope model); and (iii) BMI gain and no BMI gain among obese and non-obese patients (four-slope model).
  
  
  RESULTS
  We studied 738 patients with a mean (SD) age of 66 (11) years and BMI of 30.6 (5.2) kg/m2. During the 12-month study period, 41.2% of patients gained BMI (BMI gainers) and 58.8% experienced either loss (52.2%) or no change (6.6%) in BMI (non-BMI gainers). One-unit gain (or loss) in BMI was significantly (p < 0.001) associated with a 2.4% cost increase (or decrease) [one-slope model]. Every unit gain in BMI was associated with a 20.0% increase in costs among BMI gainers while losing one unit was associated with an 8.0% decrease in costs among non-BMI gainers (two-slope model, p < 0.01). The economic benefit associated with reducing one BMI unit was 9.4% cost decrease in obese and 2.7% in non-obese patients (4-slope model).
  
  
  CONCLUSIONS
  An increase in BMI among patients with type 2 diabetes was associated with increased 1-year direct healthcare costs. A reduction in BMI was associated with appreciable short-term economic benefits, especially in obese patients.
authors.affiliation: Medical Department, Lilly, Alcobendas, Madrid, Spain. dilla_tatiana@lilly.com
authors.forename: Tatiana
authors.initials: T
authors.lastname: Dilla
authors.forename: Amparo
authors.initials: A
authors.lastname: Valladares
authors.forename: Claudia
authors.initials: C
authors.lastname: Nicolay
authors.forename: Javier
authors.initials: J
authors.lastname: Salvador
authors.forename: Jesús
authors.initials: J
authors.lastname: Reviriego
authors.forename: María
authors.initials: M
authors.lastname: Costi
mesh_terms: D000368:Aged; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000191:economics* / Q000503:physiopathology; D005260:Female; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013030:Spain; D055105:Waist Circumference