Table 2 Percentage of returning to work at 1 year (primary outcome).

From: Intensive spa and exercise therapy program for returning to work for low back pain patients: a randomized controlled trial

  Spa therapy n = 44 Usual care n = 43 Absolute difference (95% CI) Odds ratio (95% CI)†† p-value
Without imputation
   Percentage of returning    to work at 1 year, n (%) 18/32 (56.3) 14/33 (42.4) 13.1 (−11.6;37.7) 1.72 (0.62;4.76)  
After multiple imputation (mean of 20 imputations)
   Percentage of returning    to work at 1 year, % 56.3 41.9 12.6 (−12.0;37.2) 1.69 (0.60;4.73) 0.32
  1. CI: confidence interval.
  2. Spa therapy group minus usual care group, difference of percentages adjusted on centre.
  3. ††Spa therapy group versus usual care group, odds ratio adjusted on centre.