title: Acute coronary syndromes and other forms of coronary heart disease in the National Health Service, 1997-2001.
abstract: OBJECTIVE
  1) To study the frequency and distribution of acute coronary syndromes and other forms of ischemic heart disease (IHD) as the cause of hospitalization in the Portuguese National Health Service (NHS); 2) To compare mortality from the various forms of IHD by gender in NHS hospitals in the period 1997-2001.
  
  
  METHODS
  Annual in-patient data based on Diagnosis Related Groups (DRGs) sent by each NHS hospital to the Informatics and Financial Management Institute (IGIF) using ICD-9-CM codes. After quality control of the data by IGIF, the Statistics Department of the Directorate-General of Health (GDS) studied the distribution of codes 410-414 by age group and gender. Measures of central tendency were studied and the Student's t test was used to evaluate the significance of differences between men and women in the distribution of IHD in-patients.
  
  
  RESULTS
  Acute myocardial infarction (AMI) (410) caused 7618 hospitalizations (5271 male, 2347 female) in 1997. In 2001 the number was 10,047 (6693 male, 3354 female). Other acute and subacute forms of IHD (411) were 4005 (2522 male, 1483 female) and 4100 (2618 male, 1482 female) respectively during 1997 and 2001. Angina pectoris (413) and other forms of chronic ischemic heart disease (414) were 2479 (1543 male, 936 female) and 11,293 (7951 male, 3342 female) during 1997, and 1993 (1212 male, 781 female) and 12,029 (8277 male, 3752 female) during 2001. The age (meanSD) of in-patients coded as 410 was 63.1+/-12.9/63.9+/-17.0 years in men and 72.4+/-11.6/73.1+/-11.1 years in women over the period 1997-2001. Age differences by gender were statistically significant (p < 0.001). Age for code 411 was similar to AMI in men (62.9+/-11.1 years and 63.8+/-11.7 years respectively in 1997 and 2001), but was lower in AMI cases in women (68.4+/-10.6 years and 69.3+/-10.7 years respectively in 1997 and 2001). AMI mortality was higher in 1997 (11.6% male, 22.1% female) than in 2001 (9.9% male, 19.8% female).
  
  
  CONCLUSIONS
  Acute coronary events are the cause of approximately half of the hospitalizations for IHD, in both sexes. The frequency of every form of IHD in men is higher than in women, and hospitalization occurs nine years earlier on average. Between 1997 and 2001, hospitalizations for IHD increased by over 10%, mainly for AMI (32%), although with no significant increase in age. Nevertheless, the prognosis for AMI in in-patients has improved in both sexes.
authors.affiliation: Divisõ de Estatística, Direcção-Geral da Saúde, Lisboa, Portugal. jgiria@dssaude.min.saude.pt
authors.forename: José
authors.initials: J
authors.lastname: Gíria
authors.forename: Judite
authors.initials: J
authors.lastname: Catarino
authors.forename: Evangelista
authors.initials: E
authors.lastname: Rocha
mesh_terms: D000208:Acute Disease; D000368:Aged; D000789:Angina, Unstable / Q000453:epidemiology*; D003327:Coronary Disease / Q000453:epidemiology*; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology*; D017678:Sex Distribution; D013577:Syndrome