Hypothesis / aims of study
Trials that study the effect of alpha-blockers on LUTS in general report mean changes in symptom scores. This may be problematic for both patients and clinicians. Patients won’t recognise the exact impact on symptom scores but instead summarize the subjective change as successful or not. Next, clinicians would like to know how many patients benefit from treatment. Given the multifactorial origin of LUTS, they are unable to determine who will respond to alpha-blocker treatment. To address the aforementioned problems, we have conducted an open label study. Our first aim was to assess the number of subjects that experienced symptom improvement following alpha-blocker use in daily practice. Our second aim was to find predictors of this improvement.
Study design, materials and methods
We performed an open-label single-arm observational cohort study with a six-week follow-up. Patients visiting the pharmacy with a prescription from a general practitioner (GP) or urologist were eligible for inclusion, if the alpha-blocker was prescribed for LUTS (and not nephrolithiasis or indwelling catheter use), and no earlier prescriptions were present in the preceding year. At baseline, all men completed a short questionnaire containing the IPSS and OABq-SF. After six weeks, irrespective of the actual usage of the alpha-blocker at that point in time, men completed a second questionnaire with IPSS, OABq-SF and the Patient Global Impression of Improvement (PGI-I). The prescriber completed a short questionnaire and the pharmacist provided information on concomitant drug usage.
PGI-I was the main outcome, and we categorized the responses ‘much better’ or ‘very much better’ on this question as clear improvement and all other categories as no clear improvement. Demographic, disease related and drug related information was used to identify predictors of clear improvement using logistic regression analyses. Linear regression analyses were performed with change in IPSS and OAB-q as outcomes. First univariate regression was performed. Variables with a p-value <0.25 were subsequently included in multivariable regression analyses using a non-automated step-wise forward selection strategy. Analyses were performed on both original data and on imputed data. We performed a subgroup analysis that only included patients that received their prescription from a GP, to allow interpretation for primary care.
Interpretation of results
In the studied cohort one in three patients with LUTS perceived clear symptom improvement as measured with the PGI-I six weeks after the start of an alpha-blocker. Predictors of clear improvement were the current use of alpha-blockers and the use of six or more co-medications, but only in the model based on the original data. However, odds ratios in the analysis on imputed data showed a similar trend. The increased odds for current use indicates that subjects that still used alpha-blockers after six weeks were more likely to experience clear improvement. Such a relationship was not found between current use of alpha-blockers and more objective measures of improvement as the IPSS and OABq-SF indicating that the improvement could not be attributed to changes in for example frequency of urination of episodes of incontinence. An explanation for the increased odds for subjects that took more types of medication may be that drug adherence is related to concomitant use of other types of medication. So subjects that took more types of medication may have been more adherent to alpha-blockers. The present study didn’t monitor actual intake though. Prescribing alpha-blockers by GPs for patients that have symptoms for over 24 months seems less effective.