BACKGROUND: Previous studies have suggested that variation in results
of lumbar discectomy depends on careful selection of patients. Numerous
factors have been suggested to explain this variation with no direct
examinations on this issue. The objective was to examine the use of pain
medication before and after lumbar discectomy in patients with back
pain.
METHODS: Prospective occupational cohort study (N.=151,618)
with linkage to national registers. Of the cohort members, 1538 (age 44
years) underwent discectomy. Records from purchases of pain medication
were obtained during a 3-year period before and after hospital
discharge.
RESULTS: Purchases of pain medication increased during the
follow-up period from 9.7±28.7 to 17.3±17.3 defined daily doses. Three
groups were identified: 1) with constant, relatively low pain medication
use; 2) with high use combined with further increases in purchases
until the time of surgery and only a slight decrease thereafter; and 3)
with a sharp rise in medication use before surgery and a return to no
pain medication use approximately six months after the discharge.
Non-manual profession (OR=1.34, 95% CI: 1.06 to 1.69) and open surgery
technique increased (OR=1.32, 95% CI: 1.04 to 1.67) the probability of
being included into the third group.
CONCLUSIONS: The greater decline
in the use of pain medication after discectomy was associated with a
sharp rise of that use within six months before surgery. This suggests
that lumbar discectomy may benefit especially those with acute or
subacute pain within the six-month window.