Population-based utility scores for HPV infection and oropharyngeal squamous cell carcinoma among Indigenous Australians

Background: Oropharyngeal squamous cell carcinoma (OPSCC) is associated with high mortality. Human papillomavirus (HPV) infection is a significant risk factor for OPSCC. Utilities are fundamental values representing the strength of individuals’ preferences for specific health-related outcomes. Our study aim was to work in partnership with Indigenous communities in South Australia to develop, pilot test and estimate utility scores for health states related to HPV, HPV vaccination, precursor OPSCC and its treatment, and early stage OPSCC among Indigenous Australians. 

Methods: Development and pilot testing of hypothetical HPV and OPSCC health states, specifically through the lens of being Indigenous Australian, was conducted with an Indigenous Reference Group. Six health states were decided upon, with utility scores calculated using a two-stage standard gamble approach among a large convenience sample of Indigenous Australians aged 18+ years residing in South Australia. The rank, percentage of perfect health and utility score of each health state was summarised using means, and medians at 12 months and lifetime duration. Potential differences by age, sex and residential location were assessed using the Wilcox Rank Sum test. 

Results: Data from 1011 participants was obtained. The mean utility scores decreased with increasing severity of health states, ranging from 0.91–0.92 in ‘screened, cytology normal, HPV vaccination’ and ‘screened, HPV positive, endoscopy normal’, to less than 0.90 (ranging from 0.87–0.88) in lower grade conditions (oral warts and oral intraepithelial neoplasia) and less than 0.80 (ranging from 0.75–0.79) in ‘early stage throat cancer’. Higher utility scores were observed for ‘screened, cytology normal and HPV vaccination’ among younger participants (18–40 years), for ‘early stage invasive throat cancer’ among females, and for ‘oral intraepithelial neoplasia’ and ‘early stage invasive throat cancer’ among metropolitan-dwelling participants. 

Conclusion: Among a large sample of Indigenous Australians, utility for oral HPV infection and OPSCC decreased with severity of health states. Older participants, as well as males and those residing in non-metropolitan locations, had decreased utility for high-grade cytology and early invasive cancer states. Our findings are an important contribution to cost-utility and disease prevention strategies that seek to inform policies around reducing HPV infection and OPSCC among all Australians.