Table 5

Incidence rate ratio of hospital admissions between individuals with type I diabetes compared to normal population controls at different levels of exposures of interest while adjusting for significant variables explored in table 4

Parameter estimatesVariances
CategoryIRR(SE)(95% CI)p≤ESSLevelVariance (SE)(95% CI)ESS
DIC (22299)
 Reference (SES 1, small, <1990, <5)5.888(1.395)(4.118 to 8.568)0.00013711
 SES21.132(1.017)(0.870 to 1.473)0.1749144121.272(0.047)(1.183 to 1.366)3347
31.266(1.032)(0.973 to 1.643)0.0404152530.048(0.022)(0.008 to 0.095)335
41.096(1.012)(0.854 to 1.417)0.2372137540.013(2.836)(0.003 to 10.798)147
51.391(1.043)(1.082 to 1.774)0.00451344
 Centre sizeLarge0.839(0.985)(0.709 to 0.990)0.01893974
 Date of birth90 to 940.926(0.991)(0.727 to 1.166)0.2639951
95 to 991.208(1.027)(0.917 to 1.577)0.0905651
00 to 041.288(1.047)(0.899 to 1.821)0.0825651
>051.135(1.035)(0.663 to 1.931)0.32151651
 Age at diagnosis (years)Age0.846(0.989)(0.744 to 0.965)0.0061664
  • Results are from a multivariable multilevel models estimated using MCMC. Results are reported using the mean of the posterior distribution to indicate IRR, the SD of the posterior chain is used to indicate the parameter SE, 95% posterior probability intervals (95% CI) represent the 2.5th and 97.5th centiles of the posterior distribution, and directional posterior probabilities (p≤). ESS indicates the effectiveness of MCMC chain mixing. Bayesian DIC is used to indicate model fit. The reference category comparing the IRR between cases and controls in the highest social class, small centres, born prior to 1990 and with an age at diagnosis less than 5 years is indicated, and the IRR of the exposure of interest is represented by an interaction with case–control status. The level 2 variance indicates the overdispersion parameter, the level 3 variance indicates the matched set, and the level 4 variance indicates the county at diagnosis. Age is modelled as a linear change per 5 year increase in the age at diagnosis.

  • DIC, Deviance Information Criterion; IRR, incidence rate ratio; SES, socioeconomic status.