title: A sequential test for comparing two infection rates in a randomized clinical trial, and incorporation of data accumulated after stopping.
abstract: A randomized sequential test is considered for deciding whether prophylactic antibiotic is successful in reducing infection rates following neurosurgical operations. The test is of the curtailed "gambler's ruin" type. Its operating characteristics are obtained and tabulated, and the actual medical experiment is described in some detail. The problem of how additional accumulated data, observed after stopping, due to delayed response, should be incorporated in evaluation of sequential P-values and confidence intervals is also considered.
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001699:Biometry; D002986:Clinical Trials as Topic / Q000379:methods*; D004311:Double-Blind Method; D006801:Humans; D009493:Neurosurgery; D011897:Random Allocation; D013530:Surgical Wound Infection / Q000517:prevention & control
chemical_list: D000900:Anti-Bacterial Agents