SMALL VERSUS LARGE TRIALS

[摘要] Eight small RCTs (total patients, 527) of prophylactic phototherapy reported before the 1974 start of a cooperative trial (total 922 pts.) revealed a mean difference in serum bilirubin on the 4th day of 4.73 ± 0.35 mg/dl (1 SE). Cooperative trial diff. at day 4 was 4.0 ± .22 mg/dl (approximate S.E.). Seven small studies (444 pts.) of treatment published from 1971 to 1982 revealed mean difference of 2.16 ± .33 mg/dl. Cooperative study found differences at day 4 of 2.4 ± mg/dl in 276 mature infants and 3.8 ± 0.50 mg/dl in 141 infants weighing from 2000-2499 g. The risk difference for patients requiring exchange transfusions (DerSimonian and Laird method) was 0.08 ± 0.34 for the seven small studies and 0.06 ± 0.041 for the mature infants and 0.211 ± 0.56 for those weighing 2000-2499 g. Mean quality score of ten small phototherapy trials was 0.35 + 0.021 (1 SE) compared with 0.42 ± 0.022 for 376 previously scored miscellaneous trails. It is concluded that meta-analysis of many small studies of varying quality is very close to the results of a large cooperative trial.

[学科分类] 儿科学