3.4 OPCS4

OPCS4 event table is procedure codes from hospital admission data. Obtain relevant fields.

OPCS4 <- procs %>% 
  select(c(f.eid, starts_with('f.41272.'))) %>% 
  mutate_if(is.factor, as.character)  %>% 
  arrange(f.eid) %>% 
  data.frame()

OPCS4dates <- procs %>% 
  select(c(f.eid, starts_with('f.41282.'))) %>% 
  arrange(f.eid) %>% 
  data.frame()

OPCS4_codes_long <- 
  merge_long("f.41272","f.41282",OPCS4,OPCS4dates,"OPCS4") %>% distinct() %>% filter(!is.na(code))