Table 9:

Classification performance and expected admission rates for preliminary COPD Risk Scale scores, compared with current practice at study hospitals

Total score	No. of patients	Sensitivity	Specificity	Estimated probability of serious adverse event	Estimated proportion admitted, %^*
Current practice	945	0.514	0.625	0.078	37.5
COPD Risk Scale score	844^†
0	358	1.000	0	0.022	100.0
1	121	0.912	0.454	0.040	57.6
2	196	0.809	0.601	0.072	43.2
3	54	0.603	0.835	0.125	20.0
4	74	0.515	0.897	0.209	–^‡
5	19	0.250	0.969	0.329	–
6	14	0.191	0.988	0.475	–
7	3	0.074	0.996	0.626	–
8	3	0.059	0.999	0.756	–
10	2	0.029	1	0.914	–

Note: COPD = chronic obstructive pulmonary disease.
↵* For each COPD Risk Scale score, the value shown is the estimated hospital admission rate if threshold were greater than or equal to the specified point total (e.g., if threshold were set to point total ≥ 2, 43.2% of the patients would have been admitted).
↵† Model was developed using data from the 844 patients who had no missing values.
↵‡ Threshold values ≥ 4 were deemed not clinically reasonable because of poor sensitivity.