and prescriptions for real-life studies
When studying the behavior of a cohort of patients in the dispensary world, it is useful to highlight 'lost to follow-up' patients, that is, that is to say patients who stop going to pharmacies over a given period without our knowing the reason.
A patient is considered lost to follow-up if he changes pharmacy, which is why we apply a criterion of regularity of patient attendance in a given pharmacy at 60, 90 or 120 days between 2 visits to the pharmacy, all products combined.
These patients are systematically excluded from the cohort so as not to disrupt the analyzes.
The regularity criterion
Maximum period during which the social insured is not seen in the pharmacy without being declared lost to follow-up. We propose 3 default values (60, 90 and 120 days). A high regularity criterion makes it possible to include more social insured but the follow-up will be less good (increase in the number of lost to follow-up). A low regularity criterion will restrict the population of social insurance to patients with chronic treatments for which it is necessary to go to the pharmacy regularly.
60-day regularity: social insured persons having had an issue of the selection on a date T be seen at least once at the pharmacy within 60 days of the issue, all products combined.
90-day regularity: social insureds having had a selection issue on a date T be seen at least once at the pharmacy within 90 days of the issue, all products combined.
Regularity 120 days: social insured persons having had an issue of the selection on a date T and reviewed at least once at the dispensary within 120 days of the issue, all products combined.