Novel sentiment positivity index: natural language processing of online patient forums for atopic dermatitis

Background: Atopic dermatitis (AD) significantly affects quality of life (QoL) with cutaneous manifestations and associated symptoms. Patients utilize online forums to discuss treatment options for many diseases, including AD. Unlike questionnaire-based evaluations, anonymous online discussions encourage extensive dialogue. The unstructured online narrative posts may serve as a new avenue for analysis of the overall sentiment of a treatment. This observational study aims to assess perception of different treatments for AD by developing a novel sentiment positivity index (SPI) of treatment-specific comments made to a popular online AD forum using natural language processing (NLP).

Methods: All posts were extracted from a well-known online forum dedicated to AD made in a 5-year period and mentions of specific AD treatments were identified in 28,159 posts. These posts were analyzed with a pretrained language model to determine the overall sentiment, whether positive or negative. A SPI was developed, calculated as the ratio of posts expressing positive sentiment towards a particular treatment to the total number of posts. Treatment perceived more positively by participants have a higher SPI, and treatments perceived less positively have a lower SPI.

Results: For AD treatments, there were 12,439 unique post authors with an average post length of 92 words. The SPI for all AD treatments varied from 0.116 to 0.365, with a mean of 0.221. The treatments with the highest SPI were Janus kinase (JAK) inhibitors [upadacitinib 0.365, 95% confidence interval (CI): 0.264–0.479; topical ruxolitinib 0.324, 95% CI: 0.243–0.417; and baricitinib 0.290, 95% CI: 0.161–0.466]. The treatments with the lowest SPI were topical corticosteroids (TCS) (Class V corticosteroids 0.116, 95% CI: 0.066–0.196; Class VI corticosteroids 0.128, 95% CI: 0.087–0.185).

Conclusions: For all AD therapies, the mean SPI was 0.221, consistent with lower positivity regardless of therapy. A spectrum of SPI scores was demonstrated for the treatments studied, with TCS having the lowest positivity scores. Developing the SPI using natural-language processing of online forum commentary has the potential to give insight to the patient perspective and may be applicable to other disease states. Further validation and exploration of clinical relevance are warranted.