Table 2

Predictors and their primary studies with confirmation and replication status

GroupNoPredictorsModel mentioning predictorStatus
Ocular features1Retinopathy level/DR gradeLagani et al14C,48 R70
2Proliferative DRHippisley-Cox and Coupland11*C,48 R71
3MaculopathyHippisley-Cox et al11*C,48 R71
4Visual acuity scoreLagani et al14C51
Sociodemographics5AgeMultiple studies11 42 57C,43 R55
6RaceHarris et al 11 63 (L)E3 63 Lack of evidence
7GenderHarris et al63C,62 R43
8Social deprivation scoreHippisley-Cox and Coupland11*C,59 R72
Diabetes characteristics9Type of DMIcelandic model73*C74
10Age at diagnosisUKPDS OM275*C,76 R55
11Duration of DMIcelandic model73C,48 R70
Biochemical parameters12HbA1cUKPDS OM177C,51 R49
Stratton et al,60 ISDR35*
C,78 R38
C,79 R55
14Total serum cholesterolSoedamah-Muthu et al57
C,39 R55
C,40 R53
Physical examination15DBPIcelandic model73*C74
16SBPUKPDS OM277*C,76 R55
Comorbidities17HypertensionHarris et al63C39
18DyslipidaemiaHarris et al63C,79 R80
29Psychiatric illnessLagani et al14 (L)*Absence of evidence
Diabetic complications20Chronic renal disease*Hippisley-Cox and Coupland11C81
21Diabetic nephropathyHarris et al63C,62 R37
22Diabetic neuropathyHarris et al63 (L)*Absence of evidence
Diabetes treatment23StatinHarris et al63C,82 R80
24InsulinHarris et al63*C,83 R50
Lifestyle25SmokingMcEwan et al61 (L)C,43 44 Absence of evidence
26BMIMcEwan et al and others14 42 61 (L)*C,41 Absence of evidence
27Exercise/physical activityTanaka13 (L)Absence of evidence
New from NGT28Only eye situationNA (L)Absence of evidence
29Early worseningNAC,45 R84
30Frequent DNANA (L)C47 Lack of evidence
31PregnancyNAC,46 R52
32DietNA (L)Absence of evidence
33Preproliferative DRNAC,48 R85
34Chronic infectionNA (L)Absence of evidence
35ComorbiditiesNA (L)Absence of evidence
  • *Modelling study did not clearly identify the primary study for the predictor. Details in text.

  • BMI, body mass index; C, confirmation; DBP, diastolic blood pressure; DM, diabetes mellitus; DNA, did not attend; DR, diabetic retinopathy; E, exploration; eGFR, estimated glomerular filtration rate; HbA1c, glycated haemoglobin; ISDR, Individualised Screening for Diabetic Retinopathy; L, lacking evidence; NA, not applicable; R, replication; SBP, systolic blood pressure ; UKPDS, United Kingdom prospective Diabetes Study.