Ecologic analysis of asthma-related events and dispensing of inhaled corticosteroid- and salmeterol-containing products.
BACKGROUND
An association between salmeterol use and serious asthma episodes or asthma-related mortality has been noted in 2 clinical trials; however, a causal relationship has not been established. To date, observational studies have not replicated this finding.


OBJECTIVE
To examine the relationship between number of prescriptions dispensed of salmeterol-containing products and inhaled corticosteroid (ICS)-containing products and the rates of asthma-related hospitalizations and mortality in the United States.


METHODS
In this ecologic study, annual age-adjusted rates of asthma-related hospitalization and asthma-related mortality from US population-based sources were graphed alongside annual number of prescriptions dispensed of salmeterol- and ICS-containing products by year from 1991 to 2004. We computed the Spearman rank correlations between number of prescriptions dispensed and serious events (asthma-related hospitalization rate, number of hospitalizations, asthma-related mortality rate, and number of asthma deaths).


RESULTS
During more than 14 years, while number of prescriptions dispensed of salmeterol-containing and ICS-containing products increased, age-adjusted asthma-related mortality rates declined and asthma-related hospitalization rates remained relatively stable. The number of asthma-related deaths has decreased steadily since the mid-1990s.


CONCLUSIONS
This study provides population-level evidence that asthma-related death rates declined and asthma-related hospitalization rates remained relatively constant for more than 14 years during a period of improvements in asthma management per treatment guidelines, including increased use of maintenance medications, such as ICSs and salmeterol.
DiSantostefano
Rachael L
RL
GlaxoSmithKline, Research Triangle Park, North Carolina 27709-3398, USA. Rachael.L.DiSantostefano@gsk.com
Davis
Kourtney J
KJ
Yancey
Steve
S
Crim
Courtney
C
D000280:Administration, Inhalation; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage / Q000627:therapeutic use*; D000420:Albuterol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000730:Androstadienes / Q000008:administration & dosage / Q000627:therapeutic use; D001249:Asthma / Q000188:drug therapy* / Q000401:mortality; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000627:therapeutic use; D002487:Centers for Disease Control and Prevention, U.S.; D004338:Drug Combinations; D004363:Drug Utilization / Q000706:statistics & numerical data / Q000639:trends; D000068297:Fluticasone-Salmeterol Drug Combination; D019538:Health Care Surveys; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D009309:National Center for Health Statistics, U.S.; D000068299:Salmeterol Xinafoate; D015996:Survival Rate; D014481:United States; D014798:Vital Statistics
D000305:Adrenal Cortex Hormones; D000730:Androstadienes; D001993:Bronchodilator Agents; D004338:Drug Combinations; D000068297:Fluticasone-Salmeterol Drug Combination; D000068299:Salmeterol Xinafoate; D000420:Albuterol