Before July 2007 | August 2007–December 2011 | After January 2012 | p Value | |
---|---|---|---|---|
Sample size (T1D/T2D) | 81 (77/4) | 167 (157/10) | 68 (62/6) | 0.61 |
GAD-65 assay | In house ELISA | Indirect immunofluorescence | Standardised ELISA | |
GAD-65 +ve (%) | 18.4 | 13.8 | 66.7 | <0.001 |
ICA +ve (%) | 50.6 | 38.2 | 45.0 | 0.18 |
IAA +ve (%) | 26.5 | 24.0 | 21.9 | 0.88 |
Positivity for any antibody (%) | 64.6 | 49.1 | 72.2 | 0.002 |
T2D with antibody positivity (%) | 50.0 | 10.0 | 50.0 | 0.2 |
T1D with antibody negativity (%) | 32.4 | 44.2 | 25.8 | 0.09 |
IAA, insulin autoantibody; ICA, islet cell autoantibody; GAD, glutamic acid decarboxylase; T1D, type 1A diabetes; T2D, type 2 diabetes.