Effects of socioeconomic status on baseline values and outcomes at 24 months in the Treatment of Advanced Glaucoma Study randomised controlled Trial

Abstract

Background/aims: Socioeconomic status (SES) is associated with late disease presentation and poorer outcomes. We evaluate the effect of SES on treatment outcomes and report the correlation between SES and baseline characteristics of participants in the Treatment of Advanced Glaucoma Study.

Methods: Pragmatic multicentre randomised controlled trial. Four hundred and fifty-three patients presenting with advanced open-angle glaucoma in at least one eye (Hodapp-Parrish-Anderson classification). Participants were randomised to either glaucoma drops (medical arm) or trabeculectomy (surgery arm). Clinical characteristics, Quality of life measurement (QoL) and SES defined by the Index of Multiple Deprivation are reported. Subgroup analysis explored treatment effect modifications of SES at 24 months. Correlation between SES and baseline characteristics was tested with the χ² test of association for dichotomous variables and pairwise Pearson's correlation for continuous variables.

Results: The mean visual field mean deviation was -17.2 (6.7)dB for the most deprived quintile of participants and -13.0 (5.5) for the least deprived quintile in the index eye. At diagnosis, there was a strong correlation between SES and ethnicity, age, extent of visual field loss and number of visits to opticians prior to diagnosis. At 24 months, there was no evidence that the treatment effect was moderated by SES.

Conclusions: In patients presenting with advanced glaucoma. SES at baseline is correlated with poorer visual function, poorer Visual Function Questionnaire-25 QoL, ethnicity, age and number visits to an optician in the years preceding diagnosis. SES at baseline does not have an effect of the success of treatment at 24 months.

Trial registration number: ISRCTN56878850.

Keywords: Clinical Trial; Epidemiology; Glaucoma.