Home Narrowband Ultraviolet B Phototherapy for Photoresponsive Skin Conditions: A Health Technology Assessment

Abstract

Background: Skin conditions are photoresponsive if they respond to ultraviolet (UV) radiation with partial or complete clearing. Ultraviolet phototherapy is performed by exposing the skin to UV radiation on a regular basis under medical supervision. Three types of UV radiation are used to treat photoresponsive skin conditions: broadband ultraviolet B (BB-UVB), psoralen plus ultraviolet A (PUVA), and narrowband ultraviolet B (NB-UVB). Narrowband UVB phototherapy is generally more effective than BB-UVB and safer than PUVA in the management of several photoresponsive skin conditions. While typically performed in an outpatient clinic setting, home NB-UVB phototherapy may be a viable option for people with limited access to outpatient treatment. We conducted a health technology assessment of home NB-UVB phototherapy for people with photoresponsive skin conditions that included an evaluation of the effectiveness, safety, cost-effectiveness, and budget impact of publicly funding home NB-UVB phototherapy, and patient preferences and values.

Methods: We performed a systematic literature search of the clinical evidence. We assessed the risk of bias of each included study using version 2 of the Cochrane risk-of-bias tool for randomized studies, and we assessed the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We performed a systematic economic literature search and conducted a cost-utility analysis with a 10-year horizon from a public payer perspective. The cost-utility analysis was conducted for psoriasis based on the available clinical evidence. We also analyzed the budget impact of publicly funding home NB-UVB phototherapy in people with photoresponsive skin conditions in Ontario. To contextualize the potential value of NB-UVB phototherapy, we spoke with people with photoresponsive skin conditions.

Results: We included one randomized controlled trial in the clinical evidence review. We found that home NB-UVB phototherapy is at least as effective as outpatient clinic NB-UVB phototherapy for the treatment of mild to severe psoriasis (the only photoresponsive skin condition investigated in the included study). In the included study, 82% of participants were treated at home, compared with 79% treated in an outpatient clinic setting (many participants had experience with both treatment settings). They demonstrated an improvement in baseline Psoriasis Area and Severity Index 50 (mean difference 2.8%, 95% confidence interval -8.6% to 14.2%), with the mean difference exceeding the preset noninferiority margin of -15%. Similar results were observed for other psoriasis area and severity indices (GRADE: Moderate). Episodes of mild erythema, burning sensation, severe erythema, and blistering were reported in both treatment groups, but were too few to allow a comparative safety assessment (GRADE: Low).The primary economic evaluation showed that home NB-UVB phototherapy is more costly (incremental cost $4,509) and has higher quality-adjusted life-years (QALYs; incremental QALY 0.29) than outpatient clinic NB-UVB. Our best estimate of the incremental cost-effectiveness ratio of home NB-UVB compared with outpatient clinic NB-UVB is $15,675 per QALY gained. The probability of home NB-UVB being cost-effective versus outpatient clinic NB-UVB is 77% at a willingness-to-pay of $50,000 per QALY gained. Publicly funding home NB-UVB phototherapy in the psoriasis population would lead to about $0.7 million each year and a total 5-year net budget impact of about $3.3 million. Publicly funding home treatment for people with photoresponsive skin conditions would lead to about $1.3 million each year and a total 5-year net budget impact of $6.3 million; however, this scenario accounted for the cost of phototherapy only (it did not include treatment-specific medical costs for conditions other than psoriasis).People with photoresponsive skin conditions with whom we spoke viewed home NB-UVB phototherapy as beneficial for those with health conditions that make it difficult to travel, for those with busy schedules, and for those who may not have the means to pay for travel to clinics.

Conclusions: Home NB-UVB phototherapy is at least as effective as outpatient clinic NB-UVB phototherapy for the treatment of mild to severe psoriasis (GRADE: Moderate). We are uncertain if adverse events happen more often or less often with home NB-UVB phototherapy than outpatient clinic NB-UVB phototherapy (GRADE: Low).Home NB-UVB phototherapy has an ICER of $15,675 per QALY gained, and the probability of home NB-UVB phototherapy being cost-effective is 77% at a willingness-to-pay of $50,000 per QALY gained. When accounting for the cost of phototherapy and other psoriasis-specific treatment costs (e.g., physician visits and adjuvant treatments), publicly funding home NB-UVB phototherapy in the psoriasis population would lead to a total 5-year net budget impact of about $3.3 million. Funding home NB-UVB phototherapy to people with photoresponsive skin conditions would lead to a total 5-year net budget impact of $6.3 million.People with photoresponsive skin conditions with whom we spoke viewed both outpatient clinic and home NB-UVB phototherapy to be effective treatment options.