Table 1

Summary characteristics of studies included in the systematic review (N=224)

Study characteristicsN%
Country
 Europe (including Denmark, Finland, France, Germany, Ireland, Italy, Netherlands, Spain, Sweden, Switzerland, UK)8337
 USA8237
 Canada209
 Multinational198
 Other209
Population
 Adults only6830
 Children4621
 Adults and children7533
 Not specified (including hypothetical cohorts)3516
Sample size
 <100198
 100–10009542
 >10005625
 Not specified (including economic models)5424
Asthma severity
 Mild4118
 Moderate5324
 Severe5022
 Other classification (including allergic, acute, persistent, uncontrolled)5625
 Not specified9944
Type of study
 Cohort study8337
 RCT7533
 Economic model5123
 Survey104
 Literature review63
Type of intervention
 Medication10748
 Procedures2813
 Educational interventions219
 Tests84
 Other interventions (eg, environmental, adherence)31
 Non-interventional studies (eg, surveys, cost-of-illness study)5725
Perspective of economic analysis
 Healthcare provider12254
 Societal6830
 Third-party payer (eg, insurance companies, managed care organisations)3917
 Other perspectives (eg, patients, employer)63
 Not specified219
Type of economic analysis
 Cost analysis9442
 Cost effectiveness8438
 Cost utility4118
 Cost benefit63
 Cost consequences21
 Cost minimisation21
 Other analysis (eg, resource use, literature review of economic analysis)42
Sources of economic outcomes
 Study records8940
 Registries and databases7734
 Published sources5123
 Population surveys136
 Expert panels31
 Not specified21
  • *Rounded to the nearest whole number. Some studies may belong to several groups, therefore percentages may not add to 100%.

  • RCT, randomised controlled trial.