Methods
We retrospectively analyzed the SPIRS data from 1981 through 2020,
looking at numbers of new diagnoses, care delivery sites and trial
enrollment in cooperative group studies (CCG/POG/COG). There was no
distinction between biologic and therapeutic studies in the SPIRS
database. We examined the data in 5-year increments starting in
1981-1985 and ending in 2016-2020. Joinpoint regressions were used to
estimate annual percentage changes (APCs) with the corresponding 95%
confidence intervals in log-transformed percentages.