TABLE 5-1Summary of Controlled Studies Evaluating Estimated Relative Risk (RR) of SIDS Associated with DPT Immunization

Population,Percent Immunized with DPTPowerb
ReferenceDesignYearsNo. BirthsDescriptionNo. SIDSNo. ControlsSIDSControlsRR (95% CI)a50%80%
Taylor and Emery, 1982Matched case-control1979-1982~30,000Sheffield, England2652 age-matched19370.4 (0.1-1.3)3.25.4
Pollock et al., 1984Cohort1978-198010,0286,004 and 4,024 children who received 13,917 DPT and 10,601 DT immunizations, respectively, in Hertfordshire, England7 within 6 weeks of DPT or DT immunizationCompare number of SIDS per number of DPT (3) versus DT (4) immunizations0.6 (0.1-2.3)4.07.4
Hoffman et al., 1987Matched case-control1978-1979347,800Six sites that included ~10% of U.S. births1. 716 autopsy confirmed1. 757 age-matched40550.5 (0.4-0.7)1.41.6
2. Same2. 757 age-, race-, low-birth-weight matched40530.6 (0.5-0.7)1.21.2
Walker et al., 1987Matched case-cohort1972-198326,500Members of Group Health Cooperative, Puget Sound29 healthy at birth with birth weight g262 healthy at birth with birth weight of 2,500 g, random sample age and period-matched (to generate expected number of cases)79950.2 (0.05-0.4)2.94.7
Bouvier-Colle et al., 1989Matched case-control1986Unknown322 of 522 (62%) registered deaths in France over 3 months in children ages 85 to 365 days in which physician responded to a questionnaire1. 152 of 230 (66%) registered SIDS cases1. 173 of 292 (59%) registered other deaths40291.6 (1.0-2.5)1.61.9
2. 135 of 152 item 1 above2. 401 living age-and sex-matched40470.7 (0.5-1.1)1.61.9

RR (95% CI), Estimated relative risk (95 percent confidence interval). RRs and CIs for Pollock et al. (1984), Walker et al. (1987), and Bouvier-Colle et al. (1989) were calculated by the committee using data from these reports (see Appendix D).


"Power" denotes the probability that a statistical test based on a sample of the same size as the one in the study cited would find a statistically significant increased risk (with alpha = 0.05), given that the true RR in the population being studied is the number stated in the table. The numbers tabulated are the RRs such that the powers are 50 and 80 percent, respectively.

From: 5, Evidence Concerning Pertussis Vaccines and Deaths Classified as Sudden Infant Death Syndrome

Cover of Adverse Effects of Pertussis and Rubella Vaccines
Adverse Effects of Pertussis and Rubella Vaccines: A Report of the Committee to Review the Adverse Consequences of Pertussis and Rubella Vaccines.
Institute of Medicine (US) Committee to Review the Adverse Consequences of Pertussis and Rubella Vaccines; Howson CP, Howe CJ, Fineberg HV, editors.
Washington (DC): National Academies Press (US); 1991.
Copyright © 1991 by the National Academy of Sciences.

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