From: Evaluation of the impact of disease prevention measures: a methodological note on defining incidence rates
Source
Denominator
Hennekens and Buring ([1], p.57)
“total person-time of observation”
Smith and Morrow ([2], p.306)
“person-time-at-risk”
Greenland and Rothman ([3], p.34)
“time spent in population”
Porta ([4], online version])
“number of person-time units at risk”