Analysis of static parameters in retrospective studies: limitations and interpretation

A reply to analysis of static parameters in retrospective studies: limitations and interpretation

“…We thank Dr. Shen for their interest in our study [ 1 , 2 ]. Dr. Shen raises important points on the effect of critical care interventions on blood pressure, the impact of blood pressure exposure over time on outcomes, and the clinical implications of our study [ 2 ].…”

“…The physiological data contained within the Case Mix Programme in our study are collected by trained data collectors according to strict rules set out in a Data Collection Manual [ 1 ]. These rules state blood pressure values “… should not be recorded for any admission during periods of iatrogenic disturbance, e.g.…”

“…These rules state blood pressure values “… should not be recorded for any admission during periods of iatrogenic disturbance, e.g. physiotherapy, turning, periods of crying, etc .” Therefore, the critical care interventions described by Dr. Shen will not have contributed to highest and lowest blood pressure recordings in our study [ 1 , 2 ].…”

“…Finally, Dr. Shen poses the question of how to manage a patient with a MAP ranging from 75 to 80 mmHg considering our findings [ 1 ]. Skrifvars and colleagues conducted a Beyesian model meta-analysis of randomized controlled trials to predict the likelihood of future trials detecting a benefit with a higher MAP target following cardiac arrest.…”