Mansberger 2015.

Study characteristics
Methods	Long‐term comparative effectiveness of telemedicine in providing diabetic retinopathy screening examinations: a randomized clinical trial RCT (NA clusters and NA providers), conducted in 1) We included patients from two community health clinics (Yellowhawk Tribal Health Center (Pendleton, OR) and Hunter Health Clinic (Wichita, KS)). 2) Clinic technicians performed nonmydriatic testing and transferred the retinal images using a telemedicine system to 2 experienced Devers Eye Institute investigators (S.D. and S.L.M.) for review. In United States of America. 2 arms: 1. Control (traditional surveillance with an eye care provider) (control arm) and 2. Intervention (telemedicine with a nonmydriatic camera) (intervention arm)
Participants	Control arm N: 271 Intervention arm N: 296, NA, NA Diabetes type: 4 Mean age: 51.1 ± 11.12 % Male: 48.3 Longest follow‐up: 60 months
Interventions	Control arm: (traditional surveillance with an eye care provider) 1) Facilitated relay of clinical information 2) Patient education Intervention arm: (telemedicine with a nonmydriatic camera) 1) Electronic patient registry 2) Facilitated relay of clinical information 3) Patient education
Outcomes	Retinopathy screening
Funding source	This research was supported by grant NEI 3 K23 EY0155501‐01 from the National Eye Institute, grants CDC U48DP000024‐01 and 1U48DP002673‐01 from the Centers for Disease Control and Prevention, and the Good Samaritan Foundation at Legacy Health (Dr Mansberger)
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	We used a random number generator to randomly assign participants to the telemedicine group or the traditional surveillance group.
Allocation concealment (selection bias)	Unclear risk	Not reported. We used a random number generator to randomly assign participants to the telemedicine group or the traditional surveillance group.
Patient's baseline characteristics (selection bias)	Low risk	Table 2. All P values are above 0.05 for baseline characteristics. There were no differences in demographic and medical characteristics at enrollment between the telemedicine (n = 296) and traditional surveillance (n = 271) groups.
Patient's baseline outcomes (selection bias)	Low risk	Table 2. All P values are above 0.05 for baseline outcomes. There were no differences in demographic and medical characteristics at enrollment between the telemedicine (n = 296) and traditional surveillance (n = 271) groups.
Incomplete outcome data (attrition bias)	High risk	No loss to follow‐up at 18 months (before both arms received intervention). But 133 lost to follow‐up at 5 years follow‐up (total of 23.5%, 23% in the control arm and 24% in intervention arm). Numbers balanced. Reasons not reported. The study population included a high percentage of participants who had transient housing and moved in and out of the healthcare system. Consequently, communities that display more stable housing may actually observe higher percentages of patients receiving long‐term follow‐up.
Blinding of participants and personnel (performance bias) and of outcome assessors (detection bias)	Low risk	Our outcomes of interest are objective (research staff reviewed participants’ clinic medical records at regular intervals to identify eye examination visits).
Selective reporting (reporting bias)	Unclear risk	Retrospectively registered protocol (first posted in June 2011, patients were recruited between August 2006 and September 2011). Protocol only mentions proportion of participants receiving annual eye exam; publication also reports patients requiring referral to eye care professionals and worsening of diabetic retinopathy.
Risk of contamination (other bias)	High risk	The project staff encouraged all participants to see an eye care professional once per year for a comprehensive eye examination. This could explains why so many patients had a traditional eye examination in the control group during the first 6 months. Control group received intervention after 2 years.
Other bias	Low risk	No evidence of other bias.