Table 2. Rate ratio (RR) and 95% confidence interval (CI) of cardiac death rates comparing postvaccination to reference periods,^a New York City, March–June, 1946–1948.

Outcome	Postvaccination period	RR (95% CI)
All cardiac deaths (ICD-5 090–095)	April 22–May 5	1.01 (0.96 to 1.07)
50- to 64-year-olds only		1.05 (0.95 to 1.15)
Atherosclerotic cardiac deaths (ICD-5 094)	April 22–May 5	1.06 (0.97 to 1.16)
50- to 64–year-olds only		1.00 (0.86 to 1.15)
Myopericarditis deaths (ICD-5 090, 093)	April 22–May 5	1.00 (0.94 to 1.07)
All deaths	April 22–May 5	1.00 (0.97 to 1.04)
All cardiac deaths (ICD-5 090–095)	April 16–May 13	0.99 (0.95 to 1.04)

^aAll models are adjusted for long-term temporal and seasonal trends.