Comparison of the Erectile Dysfunction Drugs Sildenafil and Tadalafil Using Patient Medication Reviews: Topic Modeling Study (Preprint)

Abstract

Topic modeling of patient medication reviews of erectile dysfunction (ED) drugs can help identify patient preferences regarding ED treatment options. The identification of a set of topics important to the patient from social network service drug reviews would inform the design of patient-centered medication counseling.

This study aimed to (1) identify the distinctive topics from patient medication reviews unique to tadalafil versus sildenafil; (2) determine if the primary topics are distributed differently for each drug and for each patient characteristic (age and time on ED drug therapy); and (3) test if the primary topics affect satisfaction with ED drug therapy controlling for patient characteristics.

Data were collected from the patient medication reviews of sildenafil and tadalafil posted on WebMD and Ask a Patient. The latent Dirichlet allocation method of natural language processing was used to identify 5 distinctive topics from the patient medication reviews on each drug. Analysis of variance and a 2-sample <i>t</i> test were conducted to compare the topic distribution and assess whether patient satisfaction varies with the primary topics, age, and time on medication for each ED drug. Statistical significance was tested at an alpha of .05.

The patient medication reviews of sildenafil (N=463) had 2 topics on treatment benefit and 1 each on medication safety, marketing claim, and treatment comparison, while the patient medication reviews of tadalafil (N=919) had 2 topics on medication safety and 1 each on the remaining subjects. Sildenafil’s reviewers quite frequently (94/463, 20.4%) mentioned <i>erection sustainability</i> as their primary topic, whereas tadalafil’s reviewers were more concerned about <i>severe medication safety</i>. Those who mentioned <i>erection sustainability</i> as their primary topic were quite satisfied with their treatment as opposed to those who mentioned <i>severe medication safety</i> as their primary topic (score 3.85 vs 2.44). The discovered topics reflected the marketing claims of <i>blue magic</i> and <i>amber romance</i> for sildenafil and tadalafil, respectively. The topic of <i>blue magic</i> was preferred among younger patients, while the topic of <i>amber romance</i> was preferred among older patients. The topic <i>alternative choices</i>, which appeared for both the ED drugs, reflected patient interest in the comparative effectiveness and price outside the drug labeling information.

The patient medication reviews of ED drugs reflect patient preferences regarding drug labeling information, marketing claims, and alternative treatment choices. The patient preferences concerning ED treatment attributes inform the design of patient-centered communication for improved ED drug therapy.