Demographic and clinical characteristics of patients.

All values are medians with interquartile ranges unless mentioned otherwise. Percentages may not total 100 due to rounding. †Weak analgesics were defined as NSAIDS, paracetamol, codeine and tramadol. Strong analgesics were defined as opioid based therapies. ‡Alcohol abusing patients were defined as female patients drinking >14 units of alcohol per week or male patients drinking >21 units of alcohol per week. ‘MEQ’ is morphine equivalents, ‘pregabalin’ is pregabalin study group and ‘placebo’ is placebo study group. No statistical differences between groups were observed.