The Oxford Laser Prostate Trial: sensitivity to change of three measures of outcome

To evaluate the sensitivity to change of outcome measures in a double-blind randomized controlled trial of transurethral resection of the prostate (TURP) and contact laser prostatectomy.

A total of 152 patients were randomized to TURP or contact laser prostatectomy using the Surgical Laser Technology (SLT) system. Preoperative data were obtained using a self-administered questionnaire containing the American Urological Association (AUA-7) symptom score, the bothersome score (benign prostatic hyperplasia impact index), and the Short Form-36 health status questionnaire (SF-36). Follow-up was at 1 and 3 months. Effect size scores were calculated to indicate the extent of change from baseline to follow-up.

Data were available on 148 patients: 72 received laser therapy and 76 received TURP. Mean change in AUA-7 score at 3 months was 7.3 in the laser arm, compared with 11.9 in the TURP arm (P < 0.05). Furthermore, substantial change was detected in both groups on the bothersome score. However, very few significant differences in SF-36 dimension scores from baseline to 3 months were detected.

The SF-36 at both baseline and follow-up indicated a similar level of health status as that reported in the general population. Subsequently, the measure did not improve on any dimensions. Our data support the claim of some researchers that shorter disease-specific indices are vital to the evaluation of treatment regimens in clinical trials, especially when the general health of the patients is similar to that of the population.