Cut-off | Author (year) | N | Per cent C-pep neg | Sens (%) | Spec (%) | Mean sens and spec | Per cent correct | PPV | NPV |
---|---|---|---|---|---|---|---|---|---|
(i) Age at diagnosis (a/d) | |||||||||
<20 | Boyle (1999) | 3613 | 7 | 20 | 97 | 59 | 92 | 36 | 94 |
≤30 | Prior (1991) | 575 | 61 | 84 | 82 | 83 | 83 | 88 | 77 |
<30 | Nielsen (1986) | 215 | 69 | 64 | 88 | 76 | 72 | 92 | 53 |
<30 | Ekpebegh (2013) | 71 | 49 | 57 | 72 | 65 | 65 | 67 | 63 |
<39 | Shields (2010) | 72 | 56 | 68 | 97 | 83 | 81 | 96 | 70 |
≤40 | Prior (1991) | 575 | 61 | 97 | 59 | 78 | 82 | 79 | 92 |
≤40 | Welborn (1983) | 121 | 21 | 84 | 85 | 85 | 85 | 60 | 95 |
≤40 | Welborn (1981) | 201 | 24 | 76 | 81 | 79 | 79 | 55 | 92 |
≤40 | Laakso* (1987) | 171 | 67 | 61 | 79 | 70 | 67 | 85 | 44 |
<45 | Boyle (1999) | 3613 | 7 | 65 | 57 | 61 | 57 | 10 | 96 |
(ii) Insulin treatment/time to insulin (tti) (a=all treatments, i=insulin-treated only) | |||||||||
on insulin (a) | Prior (1991) | 575 | 61 | 99 | 25 | 62 | 70 | 68 | 97 |
on insulin (a) | Welborn (1981) | 201 | 24 | 100 | 70 | 85 | 77 | 49 | 100 |
on insulin (a) | Boyle (1999) | 3613 | 7 | 91 | 61 | 76 | 63 | 15 | 99 |
tti≤1.5 m (i) | Shields (2010) | 72 | 56 | 80 | 56 | 68 | 69 | 70 | 69 |
tti<1y (a) | Prior (1991) | 575 | 61 | 92 | 75 | 84 | 85 | 85 | 85 |
tti<2y (a) | Welborn (1983) | 121 | 21 | 100 | 82 | 91 | 86 | 60 | 100 |
tti≤2y (i) | Laakso* (1987) | 90 | 67 | 70 | 86 | 78 | 75 | 91 | 58 |
(iii) BMI | |||||||||
<20 | Boyle (1999) | 3613 | 7 | 10 | 98 | 54 | 92 | 33 | 94 |
<25† | Prior (1991) | 575 | 61 | 34 | 92 | 63 | 57 | 87 | 47 |
<25 | Boyle (1999) | 3613 | 7 | 41 | 86 | 64 | 83 | 18 | 95 |
<27† | Prior (1991) | 575 | 61 | 87 | 63 | 75 | 78 | 79 | 76 |
≤27† | Welborn (1983) | 121 | 21 | 80 | 67 | 74 | 69 | 38 | 93 |
≤27 | Laakso* (1987) | 90 | 67 | 76 | 66 | 71 | 73 | 82 | 57 |
<28 | Balasumbryaman (2006) | 294 | 60 | 67 | 86 | 77 | 78 | 79 | 77 |
<29 | Boyle (1999) | 3613 | 7 | 71 | 57 | 64 | 58 | 11 | 96 |
<29 | Shields (2010) | 72 | 56 | 78 | 56 | 67 | 68 | 69 | 67 |
<30 | Ekpebegh (2013) | 71 | 49 | 77 | 47 | 62 | 62 | 59 | 68 |
Sensitivity (sens), specificity (spec), proportion correctly classified (%correct), mean of sensitivity and specificity (mean sens and spec), positive predictive value (PPV), and negative predictive value (NPV) for (i) age at diagnosis, (ii) body mass index (BMI) and (iii) insulin treatment and/or time to insulin. Proportion of C-peptide negative patients (% C-pep neg) shown to aid interpretation of % correct, PPV and NPV. Criteria with a mean sensitivity and specificity >70% are highlighted in bold.
*Male and female values combined, using postglucagon-stimulated results.
†Converted from percentage desirable weight.