Visual and health outcomes, measured with the activity inventory and the EQ‐5D, in visual impairment

Purpose: Generic instruments to assess health utilities can be used to express the burden of health problems in widely used indexes. That is in contrast with what can be obtained with condition-specific instruments, outcomes are very specific and difficult to compare across conditions. The purpose of this study was to assess health and visual outcomes and its determinants in patients with visual impairment (VI) using the EQ-5D-3L and the Activity Inventory (AI). Methods: Participants were recruited in different hospitals during the PCVIPstudy. A total of 134 patients with acuity 0.30 logMAR or less in the better eye were interviewed. The AI includes 46 goals split between three objectives: social functioning, recreation and daily living, and was used to measure visual ability. The EQ-5D consists of five questions covering one domain each and was used to provide a measure of health states. Responses to each domain were combined to produce a single individual index. Results: The AI and the EQ-5D-3L showed enough discriminatory power between VI levels (p < 0.001), and their results were strongly correlated r(134) = 0.825, (p < 0.001). Explanatory factors for visual ability were level of VI in better eye, age and gender, R2 = 0.43, (p < 0.001). Explanatory factors for the EQ-5D-3L were level of VI in the better eye, comorbidities and gender, R2 = 0.36, (p < 0.001). Conclusion: Our results showed that the EQ-5D-3L is useful when characterizing the burden of VI and to compute, when necessary, quality-adjusted-lifeyears (QALY) changes due to VI. However, it is important to consider that the EQ-5D-3L uses a coarse response scale, assesses a limited spectrum of domains and is influenced by comorbidities. This might limit its responsiveness to small changes in visual ability.In this study, we investigated factors affecting visual and health outcomes measured by EQ-5D and the Activity Inventory in patients with visual impairment. This study was supported by FCT (COM-PETE/QREN) grant reference PTDC/DPT-EPI/0412/2012 in the context of the Prevalence and Costs of Visual Impairment in Portugal: PCVIP-study. Authors report on behalf of the Portuguese visual impairment study group (PORVIS-group): Amandio Rocha-Sousa, MD, PhD, Ophthalmologist; Marta Silva, MD, ophthalmology resident; Sara Perestrelo, MD, ophthalmology resident; Joao Tavares-Ferreira, MD, Ophthalmologist; Ana Marta Oliveira, research coordinator; Department of Organs of Senses, Faculty of Medicine University of Porto and/or Department of Ophthalmology, Centro Hospitalar de Sao Joao and/or Unidade de Investigacao do CHSJ - Centro de Epidemiologia Hospitalar. Cristina Freitas, MD Ophthalmologist; Keissy Sousa, MD Ophthalmologist; Ricardo Leite, MD, ophthalmology resident; Jose Ferreira Mendes, MD, ophthalmology resident; Andreia Braga Soares, MD, ophthalmology resident; Rui Carneiro Freitas, MD, ophthalmology resident; Department of Ophthalmology, Hospital de Braga. Pedro Reimao, MD, Ophthalmologist; Marco Vieira, MD, Ophthalmologist; Joel Monteiro, MD, cardiology resident; Department of Ophthalmology, Centro Hospitalar de Alto Ave, Guimaraes. Natacha Moreno, MD, Ophthalmologist; Department of Ophthalmology, Hospital Sta Maria Maior, Barcelos. Gary Rubin, PhD (project adviser); UCL-Institute of Ophthalmology, London, UK. We would like to acknowledge Hospital de Braga/Ophthalmology Department and Clinical and Academic Centre and Centro Hospitalar do Alto Ave for their help at selecting and recruiting participants for this study and an anonymous reviewer for providing advice about the manuscript. Part of this work has been presented in ARVO2015 annual meeting, Denver, Colorado, and also accepted for presentation in the Public Health Conference, Milan, October 2015.