RESULTS The instruments most frequently used were single-item VAS and Biberoglu and Behrman pain score , while multidimensional inventories were used in few studies .
The results of clinical studies in CPP are more frequently based on one-dimensional measurements .
RATIONALE Many types of  pain assessment are available to research ers carrying out clinical trials in chronic pelvic pain ( CPP ) , ranging from a single-item scale to multidimensional inventories .
AIM Our objective was to investigate which assessment s of pain are more commonly used in clinical trials on CPP .
Letrozole and norethisterone acetate versus letrozole and triptorelin in the treatment of endometriosis related pain symptoms: a randomized controlled trial
Background When aromatase inhibitors are used to treat premenopausal women with endometriosis , additional drugs should be used to effectively down-regulate gonadal estrogen bio synthesis . This r and omized prospect i ve open-label study compared the efficacy in treating pain symptoms and the tolerability of letrozole combined with either norethisterone acetate or triptorelin . Methods Women with pain symptoms caused by rectovaginal endometriosis were treated with letrozole  ( 2.5 mg/day ) and were r and omized to also receive either oral norethisterone acetate ( 2.5 mg/day ; group N ) or intramuscular injection of triptorelin ( 11.25 mg every 3 months ; group T ) . The scheduled length of treatment was 6 months . A visual analogue scale and a multidimensional categorical rating scale were used to assess the severity of pain symptoms . The volume of the endometriotic nodules was estimated by ultrasonography using virtual organ computer-aided analysis . Adverse effects of treatment were recorded . Results A total of 35 women were r and omized between the two treatment protocol s. Significantly more patients in group N rated their treatment as satisfactory or very satisfactory ( 64.7 % ) as compared to group T ( 22.2 % ; p = 0.028 ) . The intensity of both non-menstrual pelvic pain and deep dyspareunia significantly decreased during treatment in both study groups , though no statistically meaningful difference between the two groups was apparent . Reduction in the volume of endometriotic nodules was significantly greater in group T than in group N. Interruption of treatment due to adverse effects significantly differed between the groups , with 8 women in group T ( 44.4 % ) and 1 woman in group N ( 5.9 % ) interrupting treatment ( p = 0.018 ) . Similarly , 14 women included in group T ( 77.8 % ) and 6 women included in group N ( 35.3 % ) experienced adverse effects of treatment ( p = 0.018 ) . During treatment , mineral bone density significantly decreased in group T but not in group N. Conclusions Aromatase inhibitors reduce the intensity of endometriosis-related pain symptoms . Combining letrozole with oral norethisterone acetate was associated with a lower incidence of adverse effects and a lower discontinuation rate than combining letrozole with triptorelin
RESULTS The instruments most frequently used were single-item VAS and Biberoglu and Behrman pain score , while multidimensional inventories were used in few studies .
The results of clinical studies in CPP are more frequently based on one-dimensional measurements .
RATIONALE Many types of  pain assessment are available to research ers carrying out clinical trials in chronic pelvic pain ( CPP ) , ranging from a single-item scale to multidimensional inventories .
AIM Our objective was to investigate which assessment s of pain are more commonly used in clinical trials on CPP .