New methods for estimating follow-up rates in cohort studies.
Xiaonan XueIlir AgalliuMimi Y KimTao WangJuan LinReza GhavamianHoward D StricklerPublished in: BMC medical research methodology (2017)
The Person-time methods correct a systematic error in the standard Percentage Method for calculating follow-up rates. The easy to use SPT and CCI methods can be used in tandem to obtain an accurate and tight interval for PTFR. However, the FPT is recommended when event rates and dropout rates are high.