. Author manuscript; available in PMC: 2019 Aug 3.

Published in final edited form as: Contemp Clin Trials. 2018 Sep 12;73:98–110. doi: 10.1016/j.cct.2018.09.004

Table 6.

Power and sample size estimates and assumptions

Outcome	Assumed Baseline (SD)	Previously Observed Change	Min Diff to Detect	Sample Size	Power
Patient Reported Outcomes
Empowerment
Intervention	98.40 (SD 9.19)	+6.64 points³⁴	6.64	500	91.4%
Intervention	98.40 (SD 9.19)	+6.64 points³⁴		550	91.9%
Control	98.40 (SD 9.19)	+0 points		600	92.3%
Control	98.40 (SD 9.19)	+0 points		997	93.9%
Self-Efficacy with self-care
Intervention	89.56 (SD 14.23)	+6.96 points³⁴	8.8 points	500	81.7%
Intervention	89.56 (SD 14.23)	+6.96 points³⁴		550	82.5%
Control	89.56 (SD 14.23)	+0 points		600	83.2%
Control	89.56 (SD 14.23)	+0 points		997	86.1%
Decision to start self-care treatment
Intervention	17%	+48%³¹	+22%	500	82.8%
Intervention	17%	+48%³¹	+22%	550	83.6%
Control	17%	+5%	+5%	600	84.3%
Control	17%	+5%	+5%	997	87.2%
Patient Biomedical Outcomes
Hospitalizations (per 1,000 patient months)
Intervention	134	76^7,85(−43%)	130 (−3%)	500	86.3%
Intervention	134	76^7,85(−43%)		550	86.7%
Control	134	134(−0%)		600	87.1%
Control	134	134(−0%)		997	88.8%
Health System Culture
Advance directives or orders documented in EHR
Intervention	12%	+65% ⁸⁶	+24%	500	80.5%
Intervention	12%	+65% ⁸⁶	+24%	550	81.3%
Control	12%	+6%	+6%	600	82.1%
Control	12%	+6%	+6%	997	85.2%