Table 4.

Direct and indirect costs in the systematic review

Author, Year of Publication, Country	Included costs	Direct medical costs	Direct non-medical or indirect (patients’) Costs	Indirect (societal) costs	Perspective year(s) of cost	Main outcomes	Main results
Pushkar & Tiwari, 2022 India [9]	Direct medical and Indirect costs	Spectacles; PRP laser; Surgical procedure; Medicine; Clinical fee; Investigation.	Travelling; Diet control; Health classes and Miscellaneous.	Not- included	Payers in 2018	Cost	Average annual direct costs INR 1,901,000 (US$ 24,142.7); indirect costs INR 10,096,000 (US$ 128,219.2). Currency Exchange Rate INR 1 = US$ 0.0127
Orji et al., 2021, India [10]	Direct medical and non- medical costs	Consultation, Investigation; PRP laser; IV injection; and Surgery	Transportation; boarding; and loading	Not-included	Payers, medical institutes, societal and third party in 2019.	Cost	Total cost of 1000 pts INR 23,767. 838 (US$ 320,865.8). Median cost per patient INR 8,214 (US$ 110). Currency Exchange Rate 1 INR = US$ 0.0135
Toth et al., 2020, Hungary [11]	Direct medical and indirect costs	Screening mobile camera; General eye exam; OCT, FA & U/S; PRP laser; and Vitrectomy.	Loss of workdays	Not-included	Satutory health insuranc and patients in 2016 and in 2045	Cost	In 2016, screening cost with no DR per pt $3.0; mild/ observable DR $46.0; referable NPDR $207.8; proliferative DR $2376.2; proliferative DMO $3517.3. In 2045, screening with no DR per pt $12.8; mild/ observable DR $7.0; referable NPDR $2.7; proliferative DR $115.4; and proliferative DMO $69.
Sasongko et al., 2019 Indonesia [12]	Direct medical and indirect costs	Screening Mobil unit transport per pt; Camera maintenance; Photographer; Medications; nurse/ field assistant. Hospital costs includes Registration; General eye exam and referral letter per visit. Additional examination OCT per eye; PRP laser; IV injection; and Vitrectomy.	Transportation cost for screening per session and referral letter per session.	Loss of workdays per day and hospital treatment.	Healthcare perspective and patients perspectives in 2017 and in 2025.	Cost	In 2017, Screening costs without DR $20 million; mild to moderate NPDR $5.9 million; VTDR requiring laser PRP $2.6 million; VTDR requiring additional IVJ anti-VEGF $1751.7 million; advanced PDR needing vitrectomy $251.6 million. In 2025, screening cost mild to moderate NPDR $92 million; laser treatment for VTDR $901.9 million; additional IVJ anti-VEGF $6279 million; and vitrectomy for advanced PDR $1587 million.
Heintz et al., 2010, Sweden [6]	Direct medical costs	Cost of hospital overheads, ophthalmologist fees, eye examinations including photographs of the retina, PRP, hospitalizations, and other resource use related to vitrectomy	Not-included	Not-included	National cost per patient principle, in 2008	Cost	Total annual healthcare cost € 9.9 million US$ 10.494 million; representing an overall healthcare cost of € 106,000 million US$ 112.36 million per 100,000 population. Currency Exchange Rate EUR 1 = US$ 1.37
Schmier et al., 2009, USA [13]	Direct medical costs	Inpatient care per beneficiary in cohort cases (NPDR and PDR ) and control in cohort. Compared to outpatient care cases (NPDR and PDR ) and control. Inpatient care for beneficiaries with one or more claim cases (NPDR and PDR) and control. compared to outpatient care cases (NPDR and PDR) and control	Not-included	Not-included	Medicare claim service from 1999 to 2004	Cost	An average annual direct cost Inpatient care for control and case groups US$ 1,223 Outpatient care for control and case groups US$ 28.
Lee et al., 2008, USA [14]	Direct medical and Indirect non-medical costs	Medical services; mean hospital inpatient stays; emergency visits; outpatient visits; and other services. Mean of prescription drugs includes OHG and insulin	Not-included	Absenteeism and disablity	Payers, Medical and prescription claims and disability claim) for 12 months	Cost	Mean annual total direct & indirect costs of DR employees ($18218 vs. $3548), respectively. Direct and indirect costs of no-DR employees ($11898 vs. $2374), respectively.
Happich & Reitberger, 2008, Germany [15]	Direct medical cost (Statutory Health Insurance GKV) and indirect (social perspective) costs	Range of medical devices; Temporary working disability; and Other services; Hospitalization; Ophthalmologist fee; Medication; Other physician fee; Transport; Further non-drug therapy; and rehabilitation	Not-included	Range of medical devices; Temporary work disability; Other services; Early retirement; Hospitalization; Ophthalmic fee; Medication; Other physician fee; Further non-drug therapy; Home help services; Rehabilitation and nursing services; and transport	GKV and societal, in 2002	Cost	Average annual social perspective € 3.51 bn (US$ 3.3345 bn) while GKV perspective € 2.23 bn (US$ 2.1185 bn). Currency Exchange Rate EUR 1 = US$ 0.95
Rein et al., 2006, USA [5]	Direct medical, direct non-medical, and indirect costs	Outpatient and inpatient visits.	Long term care; nursing home; guide dogs; independent living services for elderly blind individuals; national library services for the blind; physically handicap; and American printing house.	Productivity loss, decrease wages.	Medicare claims and MarketScan claims in 2004	Cost	Total cost of Major visual disorders $35.4 bn; Direct medical cost US$ 16.2 bn. Other direct costs US$ 11.1 bn. Productivity loss US$ 8 bn.
Phillips et al., 1994, Mexico [16]	Direct medical direct non-medical and indirect costs	Checkup; angiogram; echography; internal medicine; laboratory; PRP; cryotherapy; vitrectomy; cataract; and eyeglasses.	Transportation accommodation, and others.	Time loss; productivity loss; income loss; Disability; and percentage poor sight 51%.	Payers in 1985 and in 1991	Cost	Average cost per pt to pt Mex$ 1,549,515 (US$ 80,574.78). Average social cost of hospital treatment per pt Mex$ 1,877,035 (US$ 97,605.8). Currency Exchange Rate Mex$3 = US$1
Morsanutto et al., 2006, Italy [17]	Direct medical costs	Drugs; Visit to specialist; visit to GP; diagnosis; hospitalizations	Not-included	Not-included	National Health Service in 2002	Cost	Mean total healthcare cost of DM € 1909.67 US$2,272.50. Mean cost of single DM-related complication € 1808.17 US$ 2,151.72. Total cost per pt with DR € 1,329.9 US$ 1,582.59. Currency Exchange Rate € 1 = US$ 1.19
Schmitt et al., 2004, Switzerland [18]	Direct medical costs	Drug costs; Ambulatory costs include consultations, Outpatient diagnostic procedures, outpatient invasive procedures, and laboratory tests. Hospital care.	Not-included	Not-included	Swiss Health Insurance in 1998.	Cost	Total direct cost CHF 0.582 US$ 0.874 bn; represented 2.2% total country healthcare. Currency Exchange Rate CHF 1 = US$ 1.50
O’Brien et al., 2003, Canada [19]	Direct medical costs	Outpatient visits, labs, and laser treatment.	Not-included	Not-included	Health Insurance and government, in 2000	Cost	Blindness cost in the state US$ 1794.35 Currency Exchange Rate Cand$1 = US$ 0.85

STDR ( Sight-threatening Diabetic Retinopathy); IVJ (Intravitreal Injection); FA (Fluorescein Angiography); OCT (Ocular Coherence Tomography);

RAAB-DR (Rapid Assessment of Avoidable Blindness with the Diabetic Retinopathy Module; VTDR (Vision- threatening Diabetic Retinopathy;

PRP (Pan-retinal photocoagulation); NPDR (Non-proliferative Diabetic Retinopathy); PDR (Proliferative Diabetic Retinopathy; DME (Diabetic

Macular Edema)Macular Edema). EMR (Electronic Medical Records); MR (Medical Records); bn (billion); pt (patient).CDWO (Care Date

Warehouse in Ostergotland); NDR (National Diabetic Register); GKV(Gesetzliche Krankenversicherung); and GP (General practitioner)