title: Trends of asthma in Mexico: an 11-year analysis in a nationwide institution.
abstract: OBJECTIVE
  Asthma prevalence is increasing in many countries. Some recent articles, however, claim that this tendency is ending. Our aim was to investigate asthma trends in Mexico.
  
  
  METHODS
  Annual data on health services provided to asthmatic patients were retrospectively analyzed from 1991 to 2001.
  
  
  METHODS
  The Instituto Mexicano del Seguro Social, the largest nationwide medical institution in Mexico (approximately 24 to 32 million insured subjects).
  
  
  METHODS
  Health services provided to subjects of any age.
  
  
  METHODS
  None.
  
  
  RESULTS
  Asthma-associated health services, either expressed as absolute number or as rate per insured subjects, progressively increased until 1997 in family physician office visits (FPOVs) [newly diagnosed cases only], emergency department visits (ERVs), and hospital discharges (HDs). From that year onward, the number and rates of asthma-associated health services decreased. The same trends were observed for age groups 0 to 4 years, 5 to 14 years, 15 to 44 years, and 45 to 64 years. Using a different approach, asthma was diagnosed each year in approximately 0.4% of all FPOVs, but a decrease in this percentage was observed from 1997 onward. Likewise, asthma caused increasing percentages of all ERVs and HDs until 1997, followed by a sharp decline thereafter.
  
  
  CONCLUSIONS
  A decline in absolute and relative numbers of asthma-associated health services occurred over recent years in all medical settings, suggesting that the epidemic of new asthma cases is ending and/or that better control of the disease has been achieved.
authors.affiliation: Unidad de Investigación Médica en Epidemiología Clínica, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Mexico DF, Mexico. mhvargasb@yahoo.com.mx
authors.forename: Mario H
authors.initials: MH
authors.lastname: Vargas
authors.forename: Guillermo S
authors.initials: GS
authors.lastname: Díaz-Mejía
authors.forename: María E Y
authors.initials: ME
authors.lastname: Furuya
authors.forename: Jorge
authors.initials: J
authors.lastname: Salas
authors.forename: Alejandro
authors.initials: A
authors.lastname: Lugo
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D001249:Asthma / Q000175:diagnosis* / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005544:Forecasting; D006296:Health Services / Q000706:statistics & numerical data; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D008297:Male; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D009819:Office Visits / Q000706:statistics & numerical data; D011379:Prognosis; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution