A set of four simple performance measures reflecting adherence to guidelines predicts hospitalization: a claims-based cohort study of patients with diabetes

Figures & data

Figure 1 Classification of adherence levels.

Note: The adherence levels were measured per patient in 2011.
Abbreviations: HbA_1c, hemoglobin A_1c; HDL, high-density lipoprotein; LDL, low-density lipoprotein.

Table 1 Patients characteristics of the diabetes cohort by drug treatment group at baseline

Characteristic	Total n=40,285	Users of OAs n=28,404	Users of insulin n=4,965	Users of OAs and insulin in combination n=6,916	P-valuea
	%	%	%	%
Population characteristics and hospitalization (2011)
Sociodemographics
Male	55.1	54.6	55.4	56.7	0.005
Age group (years)					<0.001
18–39	2.9	1.3	14.0	1.9
40–59	22.3	21.0	27.1	23.7
60–79	58.2	60.4	42.5	60.6
>79	16.6	17.3	16.4	13.8
Health insurance status
Managed care model	30.2	31.7	25.9	27.0	<0.001
Deductible					<0.001
High (>CHF 500)	4.6	5.3	2.6	3.0
Low (CHF 300/500)	95.4	94.7	97.4	97.1
Hospitalization	23.4	20.5	29.4	30.9	<0.001
Use of antihypertensive drugs	76.5	77.0	63.9	83.5	<0.001
Use of lipid-lowering drugs	52.4	51.1	45.0	62.8	<0.001
Hospitalization (2013)	25.9	26.5	31.7	31.5	<0.001

Note:

a P-values refer to chi-square test across the three drug treatment groups.

Abbreviations: CHF, Swiss Francs; OAs, oral antidiabetic agents.

Table 2 Adherence to recommended diabetes care guidelines by drug treatment group

Measure of adherence (2011)	Total	Users of oral OAs	Users of insulin	Users of OAs and insulin in combination	P-valuea
	%	%	%	%
Performance measures
Annual HbA1c measurement	87.6	86.6	87.3	91.8	<0.001
Annual lipid profile
Annual total cholesterol test	65.2	66.6	58.3	64.2	<0.001
Annual HDL cholesterol test	56.5	57.5	52.1	55.9	<0.001
Annual LDL cholesterol test	19.8	19.9	19.0	20.1	0.317
Annual triglycerides test	59.0	60.0	54.0	58.5	<0.001
Annual lipid profile (total cholesterol/HDL/LDL, and triglycerides)	59.0	59.9	54.0	58.3	<0.001
Annual nephropathy status
Annual serum creatinine test	77.4	76.7	76.6	80.6	<0.001
Annual albuminuria test	13.1	11.6	17.0	16.6	<0.001
Annual nephropathy status (serum creatinine and albuminuria)	12.0	10.6	15.5	15.4	<0.001
Annual visit to an ophthalmologist	44.2	41.2	51.4	51.5	<0.001
Adherence level
Nonadherent (level 0)	29.9	32.9	27.0	20.1	<0.001
≥2 HbA1c measurements in a year (level 1)	24.0	22.3	27.3	28.7
Level 1 and annual lipid profile (level 2)	37.0	37.1	33.7	39.1
Level 2 and nephropathy status (level 3)	4.3	4.1	4.3	5.0
Level 3 and visit to an ophthalmologist (level 4)	4.8	3.7	7.7	7.2

Note:

a P-values refer to chi-square test across the drug treatment groups.

Abbreviations: HbA_1c, hemoglobin A_1c; HDL, high-density lipoprotein; LDL, low-density lipoprotein; OAs, oral antidiabetic agents.

Table 3 Proportion of patients hospitalized in 2013 by adherence level and drug treatment in 2011

	Hospitalization (2013)
	Total	Users of OAs	Users of insulin	Users of OAs and insulin in combination	P-valuea
	%	%	%	%
Adherence level (2011)
Nonadherent (level 0)	32.7	35.3	32.2	24.9	<0.001
≥2 HbA1c measurement in a year (level 1)	26.9	25.0	29.6	30.9
Level 1 and annual lipid profile (level 2)	33.6	33.7	29.6	36.3
Level 2 and nephropathy status (level 3)	3.2	3.2	2.9	3.4
Level 3 and visit to an ophthalmologist (level 4)	3.6	2.8	5.7	4.5

Note:

a P-values refer to chi-square test across the drug treatment groups.

Abbreviations: HbA_1c, hemoglobin A_1c; OAs, oral antidiabetic agents.

Figure 2 Odds ratios of hospitalization as a function of adherence level by treatment group.

Note: The thin lines represent the linear trend.
Abbreviations: OAs, oral antidiabetic agents; OR, odds ratio.

Table 4 Prediction of hospitalization by adherence level (as factor variable), including the interaction term “adherence level-drug treatment group” and adjusting for multiple comparisons

	Hospitalization (2013)
	Users of insulin		Users of oral OAs		Users of OAs and insulin in combination
	ORa	95% CI	ORa	95% CI	ORa	95% CI
Adherence level (2011)
Nonadherent (level 0)	1.00 (reference)		0.55	0.45–0.66	0.94	0.74–1.20
≥2 HbA1c measurement in a year (level 1)	0.88	0.69–1.13	0.55d	0.45–0.67	0.78c	0.62–0.97
Level 1 and annual lipid profile (level 2)	0.74b	0.58–0.94	0.48d	0.40–0.58	0.70d	0.57–0.87
Level 2 and nephropathy status (level 3)	0.57c	0.34–0.96	0.47d	0.35–0.62	0.54d	0.36–0.83
Level 3 and visit to an ophthalmologist (level 4)	0.64c	0.43–0.95	0.39d	0.29–0.53	0.43d	0.30–0.63

Notes:

a Adjusted for sociodemographics, health insurance status, hospitalization, use of antihypertensive drugs, and use of lipid lowering drugs;

b P≤0.01;

c P≤0.05;

d P≤0.001.

Abbreviations: CI, confidence interval; HbA_1c, hemoglobin A_1c; OAs, oral antidiabetic agents; OR, odds ratio.

Table 5 Prediction of hospitalization by adherence level (as interval scaled variable), including the interaction term “adherence level-drug treatment group” and adjusting for multiple comparisons

	Hospitalization (2013) by Adherence level (2011)
	ORa	95% CI
Drug treatment group
Insulin	0.87b	0.81–0.94
OAs	0.93b	0.90–0.97
OAs and insulin in combination	0.84b	0.79–0.90
OAs vs insulin	1.07	0.98–1.16
OAs and insulin in combination vs insulin	0.96	0.87–1.06
OAs and insulin in combination vs OAs	0.90c	0.84–0.97

Notes:

a Adjusted for all variables in Table 1;

b P≤0.001;

c P≤0.01.

Abbreviations: CI, confidence interval; OAs, oral antidiabetic agents; OR, odds ratio.