Comparative Performance of Comorbidity Measures in Predicting Health Outcomes in Patients with Chronic Obstructive Pulmonary Disease

Figures & data

Table 1 Patient Characteristics of the Study Cohort

Characteristics	Eligible Patients (n=428,251)	Training Dataset (n=214,126)	Validation Dataset (n=214,125)
Age, mean (SD), years	67.1 (13.2)	67.1 (13.2)	67.0 (13.2)
Male, %	256,337 (59.9)	128,034 (59.8)	128,303 (59.9)
Deyo disease categories (0–17), mean(SD)	1.7 (1.4)	1.7 (1.4)	1.7 (1.4)
Deyo score, mean(SD)	2.0 (1.9)	2.0 (1.9)	2.0 (1.9)
Elixhauser disease categories (0–30), mean(SD)	2.5 (1.8)	2.5 (1.8)	2.5 (1.8)
Elixhauser score, mean(SD)	5.4 (6.1)	5.4 (6.1)	5.4 (6.1)
Updated CDS, disease categories (0–29), mean(SD)	5.5 (3.2)	5.5 (3.2)	5.5 (3.2)
Updated CDS, score mean(SD)	4,213.0 (4,248.3)	4,215.0 (4,244.5)	4,210.9 (4,252.2)
PBDI, disease categories (0–37), mean(SD)	5.9 (3.6)	5.9 (3.6)	5.9 (3.6)
PBDI score, mean(SD)	1.1 (0.9)	1.1 (0.9)	1.1 (0.9)
Subsequent-year overall death, %	24,933 (5.8)	12,554 (5.9)	12,379 (5.8)
Subsequent-year overall hospitalization, %	116,062 (27.1)	58,172 (27.2)	57,890 (27.0)
Subsequent-year hospitalization due to CV disease^a, %	31,794 (7.4)	16,071 (7.5)	15,723 (7.3)
Subsequent-year hospitalization due to cerebrovascular disease^a, %	14,643 (3.4)	7,337 (3.4)	7,306 (3.4)
Subsequent-year hospitalization due to respiratory disease^a, %	63,416 (14.8)	31,742 (14.8)	31,674 (14.8)
Subsequent-year hospitalization due to other reasons, %	37,705 (8.8)	18,932 (8.8)	18,773 (8.8)

Note: ^aPatients may be counted for hospitalization due to multiple reasons.

Abbreviation: CV, cardiovascular.

Table 2 C-Statistics of Different Comorbidity Measures in Relation to Subsequent-Year Health Outcomes

Comorbidity Measure	Training Dataset (n=214,126)
	Hospitalization Due to
	Overall Death	Overall Hospitalization	CV Disease	Cerebro – Vascular Disease	Respiratory Disease	Other Reasons
Reference^a	0.771 (0.767,0.775)	0.662 (0.660,0.665)	0.709 (0.706,0.713)	0.702 (0.697,0.708)	0.722 (0.719,0.725)	0.521 (0.516,0.525)
Deyo version of Charlson Index	0.815 (0.811,0.818)	0.712 (0.709,0.714)	0.746 (0.742,0.750)	0.740 (0.735,0.745)	0.755 (0.752,0.758)	0.574 (0.570,0.579)
Elixhauser comorbidity measure	0.834 (0.831,0.838)	0.727 (0.725,0.730)	0.793 (0.790,0.797)	0.765 (0.760,0.770)	0.789 (0.786,0.791)	0.623 (0.618,0.627)
Updated CDS	0.808 (0.805,0.812)	0.717 (0.714,0.719)	0.762 (0.759,0.766)	0.728 (0.723,0.734)	0.757 (0.754,0.760)	0.577 (0.573,0.581)
PBDI	0.822 (0.819,0.826)	0.733 (0.731,0.735)	0.780 (0.777,0.783)	0.734 (0.729,0.739)	0.768 (0.765,0.771)	0.600 (0.596,0.605)
Comorbidity Measure	Validation Dataset (n=214,125)
	Hospitalization Due to
	Overall Death	Overall Hospitalization	CV Disease	Cerebro – Vascular Disease	Respiratory Disease	Other Reasons
Reference^a	0.768 (0.764,0.772)	0.660 (0.658,0.663)	0.707 (0.703,0.711)	0.697 (0.691,0.703)	0.723 (0.720,0.726)	0.520 (0.515,0.524)
Deyo version of Charlson Index	0.815 (0.811,0.818)	0.710 (0.707,0.712)	0.745 (0.741,0.749)	0.738 (0.733,0.744)	0.756 (0.753,0.758)	0.573 (0.568,0.577)
Elixhauser comorbidity measure	0.832 (0.829,0.836)	0.724 (0.722,0.726)	0.792 (0.789,0.796)	0.760 (0.755,0.765)	0.787 (0.785,0.790)	0.621 (0.617,0.625)
Updated CDS	0.808 (0.805,0.812)	0.714 (0.712,0.717)	0.758 (0.754,0.762)	0.723 (0.718,0.729)	0.757 (0.754,0.759)	0.576 (0.572,0.580)
PBDI	0.822 (0.819,0.826)	0.730 (0.728,0.733)	0.776 (0.773,0.780)	0.731 (0.726,0.736)	0.769 (0.766,0.771)	0.598 (0.593,0.602)

Note: ^aA model including age and sex only as predictors.

Abbreviations: CDS, chronic disease score; CV, cardiovascular; PBDI, pharmacy-based disease indicator.

Table 3 Net Reclassification Improvement of Different Comorbidity Measures in Relation to Subsequent-Year Health Outcomes

Comorbidity Measure	Training Dataset (n=214,126)
	Hospitalization Due to
	Overall Death	Overall Hospitalization	CV Disease	Cerebro – Vascular Disease	Respiratory Disease	Other Reasons
Reference^a	Ref	Ref	Ref	Ref	Ref	Ref
Deyo version of Charlson Index	20.6	18.6	16.6	14.7	15.9	10.4
Elixhauser comorbidity measure	25.7	23.8	29.0	18.4	24.8	19.9
Updated CDS	14.4	18.7	19.6	7.9	14.8	7.7
PBDI	24.1	27.0	28.2	10.9	20.8	17.5
Comorbidity Measure	Validation Dataset (n=214,125)
	Hospitalization Due to
	Overall Death	Overall Hospitalization	CV Disease	Cerebro – Vascular Disease	Respiratory Disease	Other Reasons
Reference^a	Ref	Ref	Ref	Ref	Ref	Ref
Deyo version of Charlson Index	20.7	18.9	16.8	17.0	15.5	10.2
Elixhauser comorbidity measure	25.6	23.4	29.0	18.8	24.5	19.6
Updated CDS	14.7	18.4	19.3	8.9	14.4	8.0
PBDI	24.5	26.9	28.2	12.9	20.8	16.8

Note: ^aA model including age and sex only as predictors.

Abbreviations: CDS, chronic disease score; CV, cardiovascular; PBDI, pharmacy-based disease indicator.

Figure 1 Observed and predicted probabilities of subsequent-year outcomes among individuals in deciles defined by the predicted probability of the outcome defined by the PBDI in the validation dataset (n=214,125).

Abbreviations: CV, cardiovascular; PBDI, pharmacy-based disease indicator.