Table 1 Characteristics of the extracted studies (n = 10)

Carlsson et al. [25]

Europe

38,800

40–59^b

NR

11 years^a

9.00%

All of the following:

(1) Self-reported diabetes

(2) Insulin treatment within 6 months of diagnosis

(3) Positive anti-GAD or C-peptide < 150 p/mol

18 (0.05%)

Viner et al. [19]

Europe

11,261

10^c

52.00%

20^c

4.20%

Self-reported insulin-dependent diabetes before age 30 years

47 (0.42%)

Harpsøe et al. [24]

Europe

75,008

30.2 [27.4–33.3]^b

100%

11.4 [10.2–12.5]^b

8.1^d%

First hospital contact (primary diagnoses on in- and outpatient contacts) with ICD-8–10 type 1 diabetes codes obtained from the Danish national patient register

144 (0.19%)

Tosur et al. [20]

North America, Australia, Europe

4,873

11.7–12.4 [1.06–51.3]^b

52.20%

1.0 [0.4–2.9]^b

15.2%^e

ADA criteria, with the presence of antibodies

591 (12.13%)

Nucci et al. [21]

North America, Australia, Europe

2,149

Birth cohort, measurement at different time points

47.23%

10^c

At age 2 years: 1.5%

At age 10 years: 9.0%

WHO, some with the presence of antibodies

172 (8.00%)

Herzog et al. [23]

Europe

132,207

43.89 (14.39)^a

48.25%

18.87 (5.87)^a

34.26%^e,f

All of the following:

(1) National registry record

(2) One of the following:

- Age at diagnosis < 30 years

- Insulin prescription

230 (0.17%)

Zucker et al. [15]

West Asia

1,426,362

17.3 (0.5)^b

41.50%

11.1 (5.9)^a

6.37%

All of the following:

(1) National registry record

(2) Actively using short-acting insulin

(3) Treatment with short-acting insulin initiated within 1 year of diagnosis

(4) No history of treatment with oral anti-glycemic drugs

(Antibodies in a sensitivity analysis)

777 (0.05%)

Ferrannini et al. [16]

North America

328

11 [8]^b

46.60%

3.2 [2.8]^b

N/A^g

ADA criteria, with the presence of antibodies

115 (35.06%)

Steck et al. [18]

North America

68

NR

52.90%

5.7^a

N/A^g

ADA criteria, with the presence of antibodies

25 (36.78%)

So et al. [17]

North America, Australia, Europe

3,856

13.27 (10.96)^a

47.50%

TrialNet’s Pathway to Prevention Study cohort

N/A^g

ADA criteria, with the presence of antibodies

896 (23.24%)