TABLE 1.

Pain and Disability Index during the last week of treatment

	Baseline	Controlled-release tramadol	Placebo	P*
Family and home responsibilities	4.7±2.6	3.5±2.4†	4.4±2.4	0.0001
Recreation	6.1±2.8	4.8±2.8†	5.6±2.7	0.0083
Social activity	4.1±2.7	3.2±2.5†	4.1±2.7	0.0028
Occupation	5.0±2.8	3.9±2.7†	4.6±2.8	0.0047
Sexual behaviour	3.5±2.9	3.6±3.0	3.6±2.0	0.8396
Self care	2.7±2.4	2.3±2.3	2.9±2.5	0.0089
Life support	2.3±2.4	1.5±2.1†	2.1±2.4	0.0499
Total pain and disability	28.5±14.0	22.8±14.5†	27.2±14.8	0.0004

Results presented as mean ± SD.

^*Between treatments;

^†Change from baseline P ≤ 0.0099