Commentary on "Seasonal Variation of Drug Prescription Rate for Overactive Bladder in Men Based on National Health Insurance Claims Data, 2012-2016".

To the editor,

We read with great interest the article by Kim et al. [1] titled “Seasonal Variation of Drug Prescription Rate for Overactive Bladder in Men Based on National Health Insurance Claims Data, 2012–2016.” Their findings showed that the overactive bladder (OAB) drug prescription rate varied seasonally and was significantly higher in the cold season than in the hot season, suggesting that cold weather may affect the development and aggravation of OAB symptoms in men. We would like to thank the investigators for their well-designed analysis [2]. In addition, it is very interesting to note that the authors’ findings are similar to those of our previous analysis of OAB in women. However, we would like to address some points that merit more attention.

We fully agree with the results of your study that OAB symptoms may vary with temperature. In particular, the authors suggest that they have produced good results based on national data. However, although Korea does not have a large territory, distinct temperature differences between the northern and southern regions are still to be expected. Accordingly, the drug patterns in the northern region and the drug patterns in the southern region may be different. The National Health Interview Survey (NHIS) data can be analyzed not only according to sex and age, but also by region. Therefore, if the authors had obtained or analyzed data on the regional distribution of medication use, the study would have produced better results.

Of course, the main purpose of the study was to explore the OAB drug prescription rate. I think that these results themselves are very meaningful and good conclusions have been reached. However, it is somewhat regrettable that the authors did not consider benign prostate hypertrophy (BPH) despite performing an analysis according to age. Although the NHIS data have the advantage of making it possible to distinguish between BPH and patients receiving α-blockers, this may be a source of bias in the study [3]. If the authors had also analyzed BPH medications, they might have been able to determine the proportion of patients who received both OAB medication and BPH medication. I am curious as to whether this analysis has been done, and I suggest that presenting these results would also be a very good research goal to supplement and build upon this study.