Study Type

Population-level DUS analyses are classified as ‘off the shelf’ studies.

Study Design

Population-level cohort.

Participants

Population-level analyses will include the entire source population with at least some time (typically 1 year) of data visibility available before start of study period.

Additional eligibility criteria will apply as follows:

  • Analyses of incidence of drug use will exclude prevalent users of the same drug/drug class on index date and/or in the previous (washout) year
  • The study population could be restricted to a specific subpopulation with certain socio-demographic e.g., age 18 or older, or with a history of a pre-specified clinical feature/s, e.g., people with a prior diagnosis of rheumatoid arthritis
  • In some cases, a minimum follow-up will be requested e.g., for treatment pattern analyses

 

Outcome/s

The following outcome/s will be obtained, potentially stratified by pre-specified criteria (age bands, sex, calendar year or month):

  • Population-based incidence rates of use of a drug/drug class over calendar time. Periods could be calendar  days, weeks, months, quarters or years.
  • Population-based prevalence of use of a drug/drug class on a given time point (point prevalence) or within a given time period (period prevalence). Periods could be calendar days, weeks, months, quarters or years.

Follow-up

Follow-up will start on a pre-specified calendar time point pre-defined as index date , e.g., 1st January or 1st of each month, and continue for a pre-specified time period, typically week, month, quarter or year.

Analyses

Population-level DUS analyses use the same analytical pipeline as Population-level descriptive epidemiology studies (see separate subsection). Incidence rates will have number of new users (with a pre-specified washout) in the numerator, and total population as person-years (except prevalent users) in the denominator. Prevalence will be calculated as number of users (prevalent or new) over whole source population at a specific time point (i.e., point prevalence) or over a specific time window (i.e., period prevalence). Both may be stratified by socio-demographics (e.g., age bands or sex) and/or calendar period. Additional criteria (e.g. disease severity/duration) may need to be considered and integrated as pre-specified in future studies.