We are pleased to have released new statistical coding and a Stata package to standardise the measurement and reporting of the proportion of days covered (PDC) against the TEN-SPIDERS framework.
The new open-source coding in Stata can be accessed via https://github.com/TEN-SPIDERS
A simple package has also been developed to operationalise the code into a simple executable function within Stata (StataCorp) statistical software.
Further information on how to prepare the dataset for the tenspiders Stata code and package is provided in our published manuscript:
Livori AC, Kuo TY, Ilomäki J, Kilkenny MF, Talic S, Ademi Z, Bell JS, Morton JI, Dalli LL. Standardization of measurement and reporting of medication adherence using the TEN-SPIDERS tool for claims data. Br J Clin Pharmacol. 2026. doi: 10.1002/bcp.70646. PMID: 42406590.
Type:
ssc install tenspiders
*Standard PDC calculation with adjustment for early refills and censoring at death (80% threshold to define high adherence):
use "medication.dta", clear
tenspiders, id(person_id) supply_date(spply_dt) days_supply(qty_sppld) event_date(spply_dt) numerator_start_date(1) death_date(death_date) early_refills(1)
*Adanced PDC calculation with adjustment for early refills, switching and censoring at death (90% threshold to define high adherence):
use "medication.dta", clear
tenspiders, id(person_id) supply_date(spply_dt) days_supply(qty_sppld) event_date(spply_dt) numerator_start_date(1) death_date(death_date) early_refills(1) switching(1) threshold(0.9)