Quality of published clinical trials on asthma.
The quality of 287 clinical trials on asthma treatment published between 1984 and 1997 is described in this article, using a scale adding to a maximum of 14 points. The mean quality score was 8.60 (standard deviation 1.55). Quality improved throughout time from 8.17 +/- 1.40 before 1989 until 9.55 +/- 1.66 after 1992. Several methodological issues were associated with higher quality, namely parallel design, longer length of the follow-up, complete description of the exclusion criteria, description of the initial and ending recruitment dates, higher sample size, explicit sample size calculation, blinding, full description of randomization, intention-to-treat analysis, full description of the intervention, and evaluation of bias. The higher statistical significance, however, was not associated with higher clinical trial quality.
Division of Preventive Medicine and Public Health, University of Cantabria School of Medicine, Santander, Spain.
Dolores
D
Quiñones
Javier
J
Llorca
Trinidad
T
Dierssen
Miguel
M
Delgado-Rodríguez
D001249:Asthma / Q000628:therapy*; D006801:Humans; D011643:Publishing / Q000592:standards; D016032:Randomized Controlled Trials as Topic / Q000592:standards* / Q000706:statistics & numerical data; D012107:Research Design; D013223:Statistics as Topic