[Assessment of the size of the placebo effect in treating asthma based on meta-analysis of efficacy trials of selected antiasthmatic drugs].
BACKGROUND
Many different methods of treatment use at least partially not only their obvious influence on a disease mechanism but also their non-specific effects on the patients. It can be measured using different types of indicators using both self-assessment of a patient and different types of measuring devices. The aim of this study was to assess the size of the placebo effect in asthma treatment based on analysis of previously published high-quality research of the efficacy of inhaled antiasthmatic drugs and and to investigate its dependence on the type of measurement used.


METHODS
A systematic review of the Medline database (using the Entrez PubMed browser) was done by typing international drug name in English and words: inhaled, randomised and placebo-controlled and meta-analysis of publications of the results of randomized placebo-controlled efficacy trials of the inhaled drugs used to treat asthma (454 publications - ultimately enrolled 41). For comparison, a similar method was used for hypertension treated with captopril (232 tests - ultimately enrolled 10).


RESULTS
During the investigation of its dependence on the type of indicators used it has been demonstrated that placebo effect in treatments of asthma was significantly higher (reaching even 29%) than in treatments of hypertension with captopril (17%). The share of the placebo effect was also significantly higher in the studies in which clinical (subjective) indicators were used compared with the studies using objective (based on measuring devices) indicators of drug efficacy.


CONCLUSIONS
The share of a placebo effect in treatments of asthma is higher than in treatments of hypertension and depends on the drugs efficacy indicators used (it is higher when clinical indicators are being used). This allows to draw conclusions as to the discrepancy between treatment goals of patient and physician and shows the need to take more account of such important issues as the patient's commitment to manage a disease in order to achieve his greater satisfaction.
Przychodnia Medycyny Rodzinnej w Warszawie Kierownik. k.radziwill@hipokrates.org
Konstanty
K
Radziwiłł
Jerzy
J
Kruszewski
D018927:Anti-Asthmatic Agents / Q000627:therapeutic use*; D001249:Asthma / Q000188:drug therapy* / Q000523:psychology; D002490:Central Nervous System; D004334:Drug Administration Schedule; D006801:Humans; D006973:Hypertension / Q000188:drug therapy; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data*; D010349:Patient Compliance; D015990:Placebo Effect; D010919:Placebos / Q000627:therapeutic use*; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome
D018927:Anti-Asthmatic Agents; D010919:Placebos