Table 2.
Accuracy of index tests and strategies
| Part 1 | Part 2 | Strategy type | TP | FP | TN | FN | Sensitivity% (95% CI) |
Specificity% (95% CI) |
PPV% (95% CI) |
NPV% (95% CI) |
| CAPTURE | n/a | Individual | 172 | 628 | 1484 | 161 | 51.7 (46.1 to 57.1) |
70.3 (68.3 to 72.2) |
21.5 (18.7 to 24.5) |
90.2 (88.7 to 91.6) |
| CDQ | n/a | Individual | 183 | 451 | 1661 | 150 | 55.0 (49.4 to 60.4) |
78.6 (76.8 to 80.4) |
28.9 (25.4 to 32.6) |
91.7 (90.4 to 92.9) |
| C-SBQ | n/a | Individual | 210 | 545 | 1567 | 123 | 63.1 (57.6 to 68.3) |
74.2 (72.3 to 76.1) |
27.8 (24.6 to 31.2) |
92.7 (91.4 to 3.9) |
| COPD-SQ | n/a | Individual | 184 | 479 | 1633 | 149 | 55.3 (49.7 to 60.7) |
77.3 (75.5 to 79.1) |
27.8 (24.4 to 31.3) |
91.6 (90.3 to 92.9) |
| Peak flow | n/a | Individual | 224 | 368 | 1744 | 109 | 67.3 (61.9 to 72.3) |
82.6 (80.9 to 84.2) |
37.8 (33.9 to 41.9) |
94.1 (92.9 to 95.1) |
| Microspirometry | n/a | Individual | 216 | 217 | 1895 | 117 | 64.9 (59.5 to 70.0) |
89.7 (88.4 to 91.0) |
49.9 (45.1 to 54.7) |
94.2 (93.1 to 95.2) |
| CAPTURE | Peak flow | Parallel (OR) |
257 | 863 | 1249 | 76 | 77.2 (72.3 to 81.6) |
59.1 (57.0 to 61.2) |
22.9 (20.5 to 25.5) |
94.3 (92.9 to 95.5) |
| CDQ | Peak flow | Parallel (OR) |
259 | 663 | 1449 | 74 | 77.8 (72.9 to 82.1) |
68.6 (66.6 to 70.6) |
28.1 (25.2 to 31.1) |
95.1 (93.9 to 96.2) |
| C-SBQ | Peak flow | Parallel (OR) |
268 | 729 | 1383 | 65 | 80.5 (75.8 to 84.6) |
65.5 (63.4 to 67.5) |
26.9 (24.2 to 29.7) |
95.5 (94.3 to 96.5) |
| COPD-SQ | Peak flow | Parallel (OR) |
259 | 687 | 1425 | 74 | 77.8 (72.9 to 82.1) |
67.5 (65.4 to 69.5) |
27.4 (24.6 to 30.3) |
95.1 (93.8 to 96.1) |
| CAPTURE | Microspirometry | Parallel (OR) |
262 | 764 | 1348 | 71 | 78.7 (73.9 to 83.0) |
63.8 (61.7 to 65.9) |
25.5 (22.9 to 28.3) |
95.0 (93.7 to 96.1) |
| CDQ | Microspirometry | Parallel (OR) |
261 | 585 | 1527 | 72 | 78.4 (73.6 to 82.7) |
72.3 (70.3 to 74.2) |
30.9 (2.8 to 34.1) |
95.5 (94.4 to 96.5) |
| C-SBQ | Microspirometry | Parallel (OR) |
271 | 675 | 1437 | 62 | 81.4 (76.8 to 85.4) |
68.0 (66.0 to 70.0) |
28.6 (25.8 to 31.6) |
95.9 (94.7 to 96.8) |
| COPD-SQ | Microspirometry | Parallel (OR) |
262 | 620 | 1492 | 71 | 78.7 (73.9 to 83.0) |
70.6 (68.7 to 72.6) |
29.7 (26.7 to 32.8) |
95.5 (94.3 to 96.4) |
| CAPTURE | Peak flow | Serial (AND) |
139 | 133 | 1979 | 194 | 41.7 (36.4 to 47.2) |
93.7 (92.6 to 94.7) |
51.1 (45 to 57.2) |
91.1 (89.8 to 92.2) |
| CDQ | Peak flow | Serial (AND) |
148 | 156 | 1956 | 185 | 44.4 (39.0 to 50.0) |
92.6 (91.4 to 93.7) |
48.7 (42.9 to 54.5) |
91.4 (90.1 to 92.5) |
| C-SBQ | Peak flow | Serial (AND) |
166 | 184 | 1928 | 167 | 49.8 (44.4 to 55.4) |
91.3 (90.0 to 92.5) |
47.4 (42.1 to 52.8) |
92 (90.8 to 93.2) |
| COPD-SQ | Peak flow | Serial (AND) |
149 | 160 | 1952 | 184 | 44.7 (39.3 to 50.3) |
92.4 (91.2 to 93.5) |
48.2 (42.5 to 53.9) |
91.4 (90.1 to 92.5) |
| CAPTURE | Microspirometry | Serial (AND) |
126 | 81 | 2031 | 207 | 37.8 (32.6 to 43.3) |
96.2 (95.3 to 96.9) |
60.9 (53.9 to 67.6) |
90.8 (89.5 to 91.9) |
| CDQ | Microspirometry | Serial (AND) |
138 | 83 | 2029 | 195 | 41.4 (36.1 to 46.9) |
96.1 (95.2 to 96.9) |
62.4 (55.7 to 68.8) |
91.2 (90.0 to 92.4) |
| C-SBQ | Microspirometry | Serial (AND) |
155 | 87 | 2025 | 178 | 46.5 (41.1 to 52.1) |
95.9 (94.9 to 96.7) |
64.0 (57.7 to 70.1) |
91.9 (90.7 to 93) |
| COPD-SQ | Microspirometry | Serial (AND) |
138 | 76 | 2036 | 195 | 41.4 (36.1 to 46.9) |
96.4 (95.5 to 97.2) |
64.5 (57.7 to 70.9) |
91.3 (90.0 to 92.4) |
Serial = positive on BOTH tests required for screen positivity; Parallel = positive on EITHER test required for screen positivity.
CAPTURE, COPD assessment in primary care to identify undiagnosed respiratory disease and exacerbation risk; CDQ, COPD Diagnostic Questionnaire; COPD, chronic obstructive pulmonary disease; C-SBQ, Chinese Symptom-Based Questionnaire; FN, false negative; FP, false positive; n/a, not applicable’; NPV, negative predictive value; PPV, positive predictive value; TN, true negative; TP, true positive.