Withdrawal from treatment as an outcome in the ISOLDE study of XXXX .

@entity1 @entity3045 @entity1030 @entity5023 @entity617
OBJECTIVES: To investigate the determinants of @entity1 withdrawal from our study, and the effect of these withdrawals on the outcome of treatment with inhaled corticosteroids in @entity1 with @entity1030 . DESIGN: A double-blind, placebo-controlled, randomized trial. SETTING: Eighteen outpatient centers in the United Kingdom. @entity1 : Seven hundred fifty-one @entity1 with stable @entity1030 defined clinically and as baseline postbronchodilator FEV(1) > or = 0.8 L and < 85% predicted, FEV(1)/FVC ratio < 70%, and FEV(1) change after @entity3045 < 10% of predicted. INTERVENTION: Random assignment of either 500 microg bid of inhaled @entity5023 (FP) using a spacer device or an identical placebo inhaler. Treatment was continued for 3 years or until @entity1 withdrew from follow-up. MEASUREMENTS AND RESULTS: Postbronchodilator FEV(1) was measured on three occasions before randomization and every 3 months thereafter. Health status was assessed by the disease-specific St. George Respiratory Questionnaire (SGRQ) and the modified short-form 36 questionnaire (SF-36) at baseline and every 6 months. Three hundred thirty-nine @entity1 withdrew, of whom 156 @entity1 received FP. Prescription of frequent courses of oral @entity617 was the most common reason for withdrawing as specified in the protocol (69 @entity1 in the FP group withdrew due to respiratory symptoms, compared with 93 @entity1 in the placebo group). This explained the significantly greater dropout of placebo-treated @entity1 that was most evident when FEV(1) was < 50% predicted. @entity1 withdrawing had a significantly more rapid decline in health status, measured by both the SGRQ and the SF-36 (p < 0.001). Those withdrawing from the placebo group had a more rapid decline in FEV(1) and more exacerbations than the FP-treated groups. Baseline FEV(1) was lower in dropouts than in @entity1 completing the study receiving placebo, but there was no difference between the respective groups receiving FP. CONCLUSIONS: @entity1 who withdrew from follow-up were those with the most rapidly deteriorating health status and lung function. Losing these @entity1 from the final analysis can reduce the power of a study to achieve its primary end point.
