Table 3.

Evaluation of Sensitivity of Results to Outliers (Core Group Analysis) and Regression to the Mean (One-Sided Analysis)

	Core group (admit count change of −3 to +3)				One-sided (admit count change of ≥0)
	12 Months		18 Months		12 Months		18 Months
	N	Admission rate change	N	Admission rate change	N	Admission rate change	N	Admission rate change
Diabetes
Comparison	9095	−7.3%	8945	−10.7%	7553	308.1%	7800	204.3%
Treatment	2121	−13.5%	2097	−18.0%	1664	274.2%	1739	155.4%
Difference		−6.2%***		−7.3%**		−33.9%**		−48.9%*
Heart Disease
Comparison	16099	−21.1%	15895	−24.8%	12739	273.0%	13207	172.2%
Treatment	3475	−26.0%	3448	−31.3%	2597	223.4%	2732	127.0%
Difference		−4.9%***		−6.5%**		−49.6%		−45.2%

Statistical significance of the intervention effect was tested using multivariate logistic regression for the difference-in-difference change (increase or no change versus decrease from baseline to 12- or 18-month program period) in hospital admissions and readmissions, and multivariate general linear regression was used in the analysis of average length of stay. All statistical tests controlled for age, sex, number of core diseases, and hospitalizations in prior 24 months (y/n).

^* P≤0.05, ^** P≤0.01, ^*** P≤0.001.