title: Hospitalization rates and cost in severe or complicated obesity: an Italian cohort study.
abstract: BACKGROUND
  The economic and social costs of obesity are estimated to be considerable, particularly for inpatient care. The aim of this study was to compare the hospitalization rates of individuals with severe (body mass index [BMI] ≥40 kg/m2) or complicated (BMI ≥30 kg/m2) obesity with those of the general population in two regions of Northwest Italy, and to describe absolute costs of hospitalization and their determinants.
  
  
  METHODS
  Between 1996 and 2002, 6,516 patients who were admitted for the first time to a hospital offering a nutritional rehabilitation programme for obesity were enrolled and followed-up (mean follow-up time: 7.3 years). Standardized hospitalization rates (SHRs) were computed by sex for all-cause and cause-specific hospitalization. The general population of the two regions was used as the reference population. The annual cost of hospitalization was estimated for the study cohort only at the individual level, and its association with different determinants was assessed using a multivariable linear model for longitudinal data.
  
  
  RESULTS
  SHRs of the study cohort versus the general population increased for all-cause hospitalization (males: 3.53, 95% CI 3.45-3.61; females: 3.22, 95% CI 3.18-3.26) as well as for most obesity-related conditions. The absolute median annual cost of hospitalization was 2,436 euros for males and 2,293 euros for females. Older age at cohort enrolment, BMI ≥40 kg/m2, waist circumference above the median (males: 1.26 metres; females: 1.13 metres), and the presence of co-morbidities, such as cardiovascular diseases, respiratory diseases, cancer, diseases of the musculoskeletal system and connective tissue, and mental disorders, significantly increased the absolute median annual costs of hospitalization.
  
  
  CONCLUSIONS
  The economic consequences of high hospitalization rates in obese individuals are relevant. Reducing the occurrence of co-morbidities among obese persons may be one important goal, not only for clinical reasons, but also from a public health point of view.
authors.affiliation: Unit of Cancer Epidemiology, San Giovanni Battista Hospital, CPO-Piemonte, CERMS and University of Turin, Turin, Italy. enrica.migliore@cpo.it
authors.forename: Enrica
authors.initials: E
authors.lastname: Migliore
authors.forename: Eva
authors.initials: E
authors.lastname: Pagano
authors.forename: Dario
authors.initials: D
authors.lastname: Mirabelli
authors.forename: Ileana
authors.initials: I
authors.lastname: Baldi
authors.forename: Dario
authors.initials: D
authors.lastname: Gregori
authors.forename: Carlo
authors.initials: C
authors.lastname: Zocchetti
authors.forename: Cristina
authors.initials: C
authors.lastname: Tuzzi
authors.forename: Franco
authors.initials: F
authors.lastname: Balzola
authors.forename: Maria Letizia
authors.initials: ML
authors.lastname: Petroni
authors.forename: Franco
authors.initials: F
authors.lastname: Merletti
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015992:Body Mass Index; D015331:Cohort Studies; D017281:Cost of Illness; D005006:Ethnicity; D005260:Female; D006296:Health Services / Q000191:economics; D017721:Hospital Costs; D006760:Hospitalization / Q000191:economics* / Q000706:statistics & numerical data*; D006801:Humans; D007558:Italy; D008297:Male; D001523:Mental Disorders / Q000150:complications / Q000191:economics; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000191:economics / Q000453:epidemiology*; D055105:Waist Circumference; D055815:Young Adult