Approximately 14,280 more US patients with psoriasis were estimated to initiate a biologic in Spring than in other seasons, and over 840 more biologic users switched in Spring than in Winter.
Affecting over 7.5 million adults and 0.9 million children in the United States, psoriasis flare has been shown to be exacerbated by factors that include obesity, tobacco smoking, and low humidity.
The researchers noted that few studies have examined seasonality in psoriasis flare, despite demonstrated seasonal fluctuation regarding known triggers of body weight and cigarette consumption.
“Regional differences have been found in health care resource use for psoriasis, psoriasis severity, comorbidities, and treatment response in the United States, and increasing latitude is associated with increased prevalence,” they added. “Over 17% of patients with psoriasis are treated with systemic therapy or phototherapy, an indicator of higher levels of disease severity.”
The study authors conducted a retrospective ecological study of patients with psoriasis identified in the Optum Clinformatics Data Mart (CDM) to explore seasonal patterns (winter [December- February], spring [March-May], summer [June-August], and fall [September-November]) in the incidence of initiation, discontinuation, and switching from systemic drugs.
The impact of patient characteristics and other potentially exacerbating factors (age, sex, region of residence [Northeast, Midwest, West, and South], status of comorbid psoriatic arthritis [PsA], and latitude [low and high]) were also examined regarding the outcome measures.
“The Optum CDM is commercially available in the United States. It contains longitudinal commercial and Medicare Advantage health plan data from 50 states since 2000. The claims data include member eligibility, medical and pharmacy claims, and inpatient confinements,” explained the researchers.
Of the study cohort, 2 groups were generated for each season of 2016 to 2019: patients with psoriasis who were eligible for initiating a systemic drug and those with psoriasis who were prevalent users of a systemic drug.
The systemic drug classes assessed comprised tumor necrosis factor-alpha (TNF-α) inhibitors, interleukin (IL)-12 and IL-23 inhibitors, IL-17 inhibitors, IL-23 inhibitors, any biologics, and nonbiologic systemic immunosuppressants. The outcome measures were defined as follows:
Overall, 360,787 patients with psoriasis (mean [SD] age, 54.2 [18.2] years; 52.5%, female patients; 6.4% had PsA at cohort entry) were at risk of initiating any systemic drugs between 2016 and 2019. And of these patients, 39,572 and 35,388 were at risk of drug discontinuation or switching for a biologic vs a nonbiologic systemic drug, respectively.
Findings showed that the initiation of biologic therapy in 2016-2019 peaked in spring (1.28%), followed by summer (1.11%), fall (1.08%), and winter (1.01%). Compared with spring, the incidence of initiating biologics overall was 13% lower in summer (relative rate [RR], 0.87; 95% CI, 0.82-0.92), 16% lower in fall (RR, 0.84; 95% CI, 0.84-0.95), and 21% lower in winter (RR, 0.79; 95% CI, 0.69-0.91).
The initiation trend was consistent by biologic class and patient characteristics (sex, age, and PsA status), and trends for nonbiologic systemic drugs followed a similar pattern. According to patient characteristics and other potentially exacerbating factors, those aged 30 to 39 years, male patients, who have psoriatic arthritis, and who live in the South region, at a lower altitude, and in an area with lower humidity had higher initiation of systemic therapy with the same seasonality pattern.
Moreover, the mean incidence of discontinuation of biologics was shown to be highest in summer overall and in stratified analyses, and switching of biologics was highest in spring. By drug class, discontinuation for TNF-α inhibitors and IL-17 inhibitors appeared to be highest in winter, discontinuation for IL-12/IL-23 inhibitors appeared to be highest in summer, and incidence of switching from TNF-α inhibitors and IL-17 inhibitors appeared to be higher than that of switching from IL-12/IL-23 inhibitors.
The researchers noted that the seasonality pattern was less clear for nonbiologic systemic drugs.
“Discontinuing ineffective drugs and switching to alternative systemic drugs among individuals who use medications in reaction to psoriasis symptoms might be a key component in reducing the risk of psoriasis worsening,” they concluded. “Future research may focus on specific systemic drug survival rate and switching patterns among patients with certain comorbidities.”
Liang H, Kirk B, Polinski JM, Yue X, Kilpatrick RD, Gelfand JM. Impact of season and other factors on initiation, discontinuation and switching of systemic drug therapy in patients with psoriasis – a retrospective study. JID Innov. Published online November 17, 2022. doi:10.1016/j.xjidi.2022.100171