Author, yearAdequate randomization?Blinding?Maintenance of comparable groups?Loss to follow-up?Measures equal, reliable, valid?Clear definition of interventions?Important outcomes considered?Intention-to-treat analysis?Quality rating for internal validityQuality rating for external validityLimitations
IBIS, 200259 YesYesMore stopped tamoxifen than placebo due to side effects77% loss in tamoxifen and 73% loss in placebo group at 60 monthsYesYesYesYesFair to goodGood for similar higher risk womenLoss to follow-up
Fisher et al, 199860 YesYesYes; loss to follow-up similar33% loss at >48 months; 63% loss at >60 monthsYesYesYesYesFair to goodGood for similar higher risk womenLoss to follow-up
Powles et al, 199861 YesYesMore stopped tamoxifen than placebo due to side effects42% loss at 70 monthsYesYesYesYesFair to goodGood for similar higher risk womenLoss to follow-up
Veronesi et al, 199862 Not providedYesNot provided96% loss at 60 monthsYesYesYesYesFairFair; women in study have hysterectomyHigh loss to follow-up; not assessed for breast cancer risk
Cummings et al, 199964 YesYesMore stopped raloxifene than placebo due to side effects22% of raloxifene, 25% of placebo with loss to follow-up at 36 monthsYesYesYesYesGoodFair; women in study have osteoporosisSubjects selected for osteoporosis risk, not breast cancer risk

From: Appendix P. Quality Ratings of Chemoprevention Trials

Cover of Genetic Risk Assessment and BRCA Mutation Testing for Breast and Ovarian Cancer Susceptibility
Genetic Risk Assessment and BRCA Mutation Testing for Breast and Ovarian Cancer Susceptibility [Internet].
Evidence Syntheses, No. 37.
Nelson HD, Huffman LH, Fu R, et al.

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