Table 1.
New cases of diabetes and kappa agreement by clearance period and exclusion criteria
| Exclusion criteria for prevalent case | ||||||
|---|---|---|---|---|---|---|
| One hit method | NDSS* method | |||||
| Clearance period (years) | Number of new cases | Incidence proportion** | Kappa agreement*** | Number of new cases | Incidence proportion** | Kappa agreement*** |
| 1 | 91872 | 2.9% | 0.427 (0.420-0.432)†,§ |
91872 | 2.9% | 0.482 (0.479-0.485)†,§ |
| 2 | 52508 | 1.7% | 0.739 (0.731-0.742)†,§ |
52508 | 1.7% | 0.810 (0.801-0.822)†,§ |
| 3 | 43473 | 1.4% | 0.849 (0.845-0.851)†,§ |
45525 | 1.5% | 0.898 (0.896-0.900)†,§ |
| 4 | 39595 | 1.33% | 0.900 (0.900-0905)†,§ |
42791 | 1.4% | 0.936 (0.933-0.937)†,§ |
| 5 | 37473 | 1.23% | 0.935 (0.933-0.937)†,§ |
41261 | 1.3% | 0.957 (0.956-0.958)†,§ |
| 6 | 36111 | 1.16% | 0.957 (0.955-0.958)†,§ |
40218 | 1.29% | 0.971 (0.970-0.973)†,§ |
| 7 | 35094 | 1.14% | 0.973 (0.972-0.974)†,§ |
39475 | 1.28% | 0.982 (0.981-0.983)†,§ |
| 8 | 34400 | 1.11% | 0.985 (0.983-0.986)†,§ |
38975 | 1.26% | 0.990 (0.989-0.991)†,§ |
| 9 | 33932 | 1.09% | 0.993 (0.992-0.994)†,§ |
38627 | 1.25% | 0.996 (0.995-0.996)†,§ |
| 10 | 33498 | 1.08% | 100 | 38342 | 1.24% | 100 |
*: National Diabetes Surveillance System case definition in Canada.
**: Incidence proportion = (Number of incident cases of diabetes for the year 2002/population at risk of diabetes for the year 2002)*100; number of diabetes cases for the year 2002 using NDSS case definition criteria is 263,213; population of 20 years old or older for the year 2002 is 5,686,255;
***: Agreement between 10 years (expected) and observed clearance period according to the clearance period and exclusion criteria for prevalent case;
†: 95%Confidence interval;
§: P < 0.0001, Chi-square test statistic for homogeneity.