Table 3 Variation in goodness of fit and optimal change point based on different models for the proportion of infective endocarditis cases associated with streptococcal organisms. For each model type, the month of change which gives the best model fit is shown, with best overall models shown in bold italics. AIC measures model goodness of fit (the lower the value the better the fit, within each set of inclusion criteria)
Inclusion criteria | Model type | AIC | Month of change (uncertainty interval) | |
|---|---|---|---|---|
Proportion of cases with a HES streptococcal code (including mixtures), out of all cases with any HES organism code | Criteria A (Sensitivity/PPV) | One change in trend, with step | 1494.8 | Oct 2008 (Dec 2005–Oct 2015) |
One change in trend, no step | 1498.3 | Apr 2002 (Oct 1997–Sep 2016) | ||
Single overall trend | 1498.7 | NA | ||
No trend, with step | 1493.4 | Oct 2008 (Mar 2006–Apr 2010) | ||
Criteria B (Specificity/PPV) | One change in trend, with step | 1415.1 | Oct 2015 (Aug 2005–Dec 2015) | |
One change in trend, no step | 1417.0 | Sep 2011 (Oct 1997–Sep 2016) | ||
Single overall trend | 1416.2 | NA | ||
No trend, with step | 1413.3 | Jun 2013 (Oct 1997–Sep 2016) | ||
Criteria C (Prior study) | One change in trend, with step | 1508.4 | Dec 2012 (Nov 2012–Oct 2013) | |
One change in trend, no step | 1516.5 | Dec 2010 (Oct 1997–Sep 2016) | ||
Single overall trend | 1516.6 | NA | ||
No trend, with step | 1511.6 | Dec 2012 (Apr 1999–May 2016) | ||
Proportion of cases matched to an SGSS oral streptococcus sample (including mixtures), out of cases matched to any SGSS organism sample | Criteria A (Sensitivity/PPV) | One change in trend, with step | 952.5 | Mar 2008 (Mar 2007–Oct 2013) |
One change in trend, no step | 951.6 | Dec 2008 (Jun 2007–Sep 2012) | ||
Single overall trend | 970.4 | NA | ||
No trend, with step | 960.1 | Aug 2015 (Apr 2003–Oct 2015) | ||
Criteria B (Specificity/PPV) | One change in trend, with step | 894.0 | Sep 2013 (Mar 2006–Oct 2015) | |
One change in trend, no step | 892.9 | May 2009 (Jan 2007–Feb 2015) | ||
Single overall trend | 902.5 | NA | ||
No trend, with step | 892.6 | Aug 2015 (Sep 2013–Nov 2015) | ||
Criteria C (Prior study) | One change in trend, with step | 907.3 | Oct 2013 (Mar 2007–Oct 2015) | |
One change in trend, no step | 906.6 | Jun 2012 (May 2007–Jun 2014) | ||
Single overall trend | 919.2 | NA | ||
No trend, with step | 907.0 | Sep 2015 (Sep 2013–Nov 2015) | ||