Assessment of adherence to visual correction and occlusion therapy in the Infant Aphakia Treatment Study

Occlusion therapy throughout early childhood is believed to be efficacious in treating deprivation amblyopia but has not been rigorously assessed in clinical trials. Further, tools to assess adherence to such therapy over an extended period of time are lacking. Using data from the Infant Aphakia Treatment Study, a randomized clinical trial of treatment for unilateral congenital cataract, we examined the use of quarterly 48-h recall interviews and annual 7-day prospective diaries to assess reported hours of patching in 114 children throughout the first 5 years of life. Consistency of data reported was assessed using correlation coefficients and intraclass correlation coefficients. Both interview and diary data showed excellent consistency with Cronbach’s Alpha’s ranging from 0.69 to 0.88 for hours of patching and 0.60 to 0.73 for hours of sleep. However, caregivers reported somewhat more adherence in prospective diaries than retrospective interviews. Completion rates, on the other hand, were substantially higher for telephone interviews than prospective diaries. For example, four years after surgery response rates to telephone interviews exceeded 75% versus completion rates of only 54% for diaries. In situations where occlusion dose monitors cannot be used for assessing adherence to occlusion therapy, such as in infants or over an extended period of time, quantitative assessments of occlusion therapy can be obtained by parental report, either as a series of prospective diaries or a series of recall interviews.