The STAR system was implemented at MSKCC in one surgeon's clinic as a pilot in April 2009. The system was made available in all clinics in June 2009. All new patients undergoing radical prostatectomy with Email addresses were eligible as well as patients treated up to four years before the start of the project (April 2005). The database was closed for analysis in February 2010. A total of 1,581 men had been sent at least one email inviting them to complete an online questionnaire in this time (approximately 50% of patients provided an email address). Of these, 1,235 completed at least one survey for an overall response rate of 78%. Russian and Spanish language versions of the instrument are available by clicking a link on the STAR portal; however, fewer than 1% of users accessed the questionnaire in a foreign language. Table shows the characteristics of the men who did and did not complete a survey. Overall there were no obvious differences between groups (Table ).
Summary of patient characteristics.
Nearly all surveys were completed in their entirety (n = 1761; 93%); 78 (4%) questionnaires included one missed question and only 48 (3%) included more than one missed question.
Table shows Cronbach's alpha coefficient 0.84, 0.86 and 0.97 for bowel, urinary and sexual function respectively. To test whether the three questionnaires were measuring separate aspects of function, we calculated correlations for all pairs of questions. Survey questions assessing the same function (potency, continence or bowel function) were more highly correlated (mean within-function correlation coefficients of 0.83, 0.54 and 0.74 for erectile, urinary and bowel function) than measures assessing different functions (mean between-function correlation coefficients of 0.17, 0.15 and 0.31 for erectile and urinary, erectile and bowel, and urinary and bowel respectively).
Summary of response rate and average scores for each domain.
We hypothesized that, if our instrument was valid, there should be a positive correlation between function and quality of life, with urinary function having a higher correlation than sexual function. This is indeed what we found: the correlations between total sexual and urinary function and overall quality of life were 0.27 and 0.47, respectively.
Table shows that age, time for surgery, and nerve sparing status were all significantly associated with both urinary and sexual function in the hypothesized direction. An increasing number of comorbidities was significantly associated with poorer urinary and sexual function (p = 0.028 and p = 0.019, respectively). Men with three or more comorbidities had on average a 7 point lower urinary score and a 13 point lower sexual function score than those without any comorbidity.
Predictors for urinary and sexual function scores.
Figure illustrates the association between time from surgery and recovery of function. We hypothesized that erectile and urinary function would increase with time from surgery, and that erectile function would continue to improve for a longer time than urinary function. Both erectile and urinary function improve significantly (both p < 0.001), particularly within the first year after surgery; as hypothesized, erectile function continues to improve beyond one year, whereas urinary function plateaus.
Figure 1 Recovery of sexual (black lines) and urinary (gray lines) function by time from surgery. Values are reported for a man with one comorbidity who received bilateral nerve sparing and was age 62 at surgery. Scores have been rescaled so that the maximum scores (more ...)
Our second hypothesis was that both erectile and urinary function would decrease with age, and that this decrease would be larger for sexual as compared to urinary function. Figure illustrates older men have much lower sexual function one year after surgery: at age 55 the mean adjusted 12 month erectile function score was 58 (95% CI: 53, 64); by age 70 it had declined to 34 (95% CI: 28, 40). Urinary function appeared to remain relatively constant until about age 70 (adjusted urinary scores were 86 [95% CI: 83, 90] and 82 [95% CI: 78, 86] at age 55 and 70, respectively), after which point we saw small decreases in reported function (adjusted score at age 75 was 75 [95% CI: 68, 82]).
Figure 2 Recovery of sexual (black lines) and urinary (gray lines) function by age at the time of surgery. Values are reported for a man 12 months after surgery who had one comorbidity and who received bilateral nerve sparing. Scores have been rescaled so that (more ...)
Our third hypothesis was that patient-reported sexual and urinary function scores would predict physician-reported assessments of potency and continence. Among those with patient and physician reported scores that were measured within six weeks of each other (n = 365 and 469 for sexual and urinary function, respectively), we found that patient-reported sexual and urinary function scores predicted physician-assessed function with high discrimination (sexual function AUC: 0.86 and urinary function AUC: 0.87; p < 0.001 for both).