Intracluster correlation coefficients for sample size calculations related to cardiovascular disease prevention and management in primary care practices

Table 2 ICC estimates for process of care outcomes

Quality of Care Indicator*	N	Average cluster size	Proportion ^Ɨ	ICC
All patients (n = 5140)
One blood pressure reading	5133	61	0.93	0.052
Two blood pressure readings	5129	61	0.75	0.111
Lipid profile	5133	61	0.78	0.076
Fasting blood glucose	5133	61	0.81	0.045
eGFR	5133	61	0.80	0.066
ACR	5133	61	0.36	0.122
Smoking status checked	5132	61	0.96	0.088
Waist circumference	5140	61	0.10	0.173
Patients with Hypertension (n = 3959)
One blood pressure reading	3959	47	0.95	0.045
Two blood pressure readings	3957	47	0.80	0.115
Anti-hypertensive medication	3959	47	0.94	0.015
Patients with Dyslipidemia (n = 4289)
Lipid profile	4289	51	0.83	0.050
Lipid lowering medication	4289	51	0.91	0.019
Patients with Diabetes (n = 2404)
HbA1c	2402	29	0.87	0.091
Glycemic Medication	2402	29	0.80	0.041
1 blood pressure reading	2404	29	0.93	0.063
2 blood pressure reading	2404	29	0.76	0.133
Lipid Profile	2404	29	0.81	0.094
Fasting blood glucose	2404	29	0.85	0.097
eGFR	2404	29	0.84	0.087
ACR	2404	29	0.56	0.167
Patients with Chronic Kidney Disease (n = 975)
eGFR	975	12	0.92	0.064
ACR	975	12	0.52	0.123
1 blood pressure reading	975	12	0.95	0.074
2 blood pressure readings	974	12	0.83	0.157
Patients with Coronary Artery Disease (n = 1573)
Medication	1573	19	0.89	0.017
1 blood pressure reading	1573	19	0.92	0.091
2 blood pressure readings	1572	19	0.77	0.137
Lipid profile	1573	19	0.75	0.104
Patients who smoke (n = 1082)
Smoking advice	1082	13	0.53	0.120
Smoking program	1082	13	0.08	0.148
Smoking cessation drug	1082	13	0.23	0.054

*whether specified quality of care indicator was discussed, recommended, or performed during a one year timeframe, ^Ɨrepresents the proportion of patients that received the listed clinical manoeuvre.
eGFR – Estimated Glomerular Filtration Rate; ACR – Albumin-to-Creatinine ratio; HbA1c – Hemoglobin A1c.

ISSN: 1756-0500