I have collected data from patient records for a specific outcome measure (outcome X) in a cohort of patients with a specific disease (disease Y). However, not all of the patients with disease Y completed the test to measure outcome X. I am writing up a case series of patients with disease Y who had positive outcome X.
When reporting estimated prevalence of outcome X in patients with disease Y, should I assess prevalence against the whole population with disease Y, or should I only assess prevalence against those patients with disease Y who completed the test to measure outcome X?
Any help much appreciated
Since you don't know whether or not the patients with Y who were not assessed for X actually had X, I would recommend that you express prevalence(%) of X in Y as no. of X in patients with Y/ no. of patients with Y tested for X ) x 100
I suggest delete the incomplete test result and assess prevalence against those completed the test to measure outcome.
Agree with James Leigh Moslim Mohsin Khalaf
Prevalence denominator should be restricted to those who completed the test to measure outcome X
Hay que tener bien claro el concepto de evaluación, esta puede conceptualizarse como un proceso dinámico, continuo, sistemático, o sea, la evaluación es un proceso y no un momento determinado. Los estudios de prevalencia son estudios de corte transversal.