Results of regression analyses for dementia diagnosis and antidementia drug prescriptions
| Years | Dementia diagnosis | Numbers of antidementia drug prescriptions | Cost of antidementia drugs compared with overall spending | |||
|---|---|---|---|---|---|---|
| Estimate* (95% CI) | p Value | Estimate† (95% CI) | p Value | Estimate‡ (95% CI) | p Value | |
| <0.001 | <0.001 | <0.001 | ||||
| 2006 | 0.96 (0.53 to 0.97) | No data available | No data available | |||
| 2007 | 0.98 (0.97 to 0.98) | No data available | No data available | |||
| 2008 | 0.94 (0.93 to 0.95) | 0.88 (0.84 to 0.92) | −0.95 (−1.13 to −0.68) | |||
| 2009 | Reference year | |||||
| 2010 | 1.04 (1.03 to 1.05) | 1.11 (1.06 to 1.16) | 0.54 (0.27 to 0.81) | |||
| 2011 | 1.12 (1.11 to 1.13) | 1.24 (1.19 to 1.29) | 2.26 (1.99 to 2.53) | |||
*Estimates represent incidence rate ratio of dementia diagnosis relative to year 2009 obtained from negative binomial regression, offset against population at risk.
†Estimates represent incidence rate ratio of number of antidementia drug prescriptions relative to year 2009 obtained from negative binomial regression, offset against total number of prescriptions.
‡Estimates represent the mean difference in relative cost of dementia drug obtained by multilevel linear regression compared with 2009.