Table 2. Diagnostic accuracy of clinical and laboratory parameters for dengue virus infection cohort, Singapore*.
| Parameter | Sensitivity (95% CI) | Specificity (95% CI) | PPV (95% CI) | NPV (95% CI) | LRP (95% CI) | LRN (95% CI) |
|---|---|---|---|---|---|---|
| Clinical | ||||||
| Documented fever >37.5°C | 0.57 (0.50–0.64) | 0.64 (0.56–0.73) | 0.68 (0.60–0.75) | 0.54 (0.46–0.61) | 3.13 (2.48–3.94) | 0.61 (0.54–0.69) |
| Headache | 0.84 (0.79–0.90) | 0.30 (0.22–0.37) | 0.61 (0.55–0.67) | 0.60 (0.48–0.71) | 1.20 (1.06–1.36) | 0.52 (0.34–0.80) |
| Myalgia | 0.76 (0.70–0.82) | 0.35 (0.27–0.43) | 0.6 (0.54–0.67) | 0.53 (0.42–0.63) | 1.17 (1.005–1.35) | 0.69 (0.49–0.98) |
| Arthralgia | 0.62 (0.55–0.69) | 0.44 (0.36–0.53) | 0.59 (0.52–0.66) | 0.47 (0.36–0.56) | 1.11 (0.92–1.34) | 0.86 (0.66–1.12) |
| Rash | 0.30 (0.23–0.37) | 0.64 (0.56–0.73) | 0.52 (0.43–0.62) | 0.42 (0.35–0.48) | 0.85 (0.62–1.17) | 1.08 (0.92- 1.27) |
| Conjunctivitis | 0.05 (0.01–0.08) | 0.90 (0.85–0.95) | 0.38 (0.17–0.59) | 0.42 (0.37–0.48) | 0.47 (0.20–1.11) | 1.06 (0.99–1.13) |
| Nausea | 0.71 (0.65–0.78) | 0.44 (0.36–0.53) | 0.63 (0.56–0.69) | 0.54 (0.45–0.64) | 1.29 (1.08–1.54) | 0.64 (0.48–0.87) |
| Vomiting | 0.29 (0.22–0.35) | 0.76 (0.68–0.83) | 0.60 (0.50–0.71) | 0.45 (0.38–0.51) | 1.17 (0.80–1.71) | 0.94 (0.83–1.08) |
| Diarrhea | 0.38 (0.31–0.45) | 0.79 (0.72–0.86) | 0.70 (0.61–0.79) | 0.50 (0.43–0.56) | 1.82 (1.24–2.66) | 0.79 (0.68–0.91) |
| Abdominal pain | 0.17 (0.12–0.23) | 0.87 (0.82–0.93) | 0.64 (0.50–0.78) | 0.45 (0.39–0.51) | 1.36 (0.78–2.36) | 0.95 (0.86–1.04) |
| Runny nose | 0.08 (0.04–0.12) | 0.79 (0.72–0.86) | 0.33 (0.19- 0.48) | 0.40 (0.34- 0.46) | 0.39 (0.21–0.70) | 1.16 (1.05–1.28) |
| Sore throat | 0.22 (0.16–0.28) | 0.67 (0.59–0.75) | 0.46 (0.36- 0.57) | 0.40 (0.33–0.46) | 0.67 (0.46–0.96) | 1.17 (1.01–1.35) |
| Cough | 0.25 (0.19–0.32) | 0.60 (0.52–0.68) | 0.45 (0.35–0.55) | 0.38 (0.32–0.45) | 0.63 (0.45–0.87) | 1.25 (1.06–1.47) |
| Breathlessness |
0.05 (0.01–0.08) |
0.97 (0.94–1.00) |
0.67 (0.40–0.93) |
0.44 (0.38–0.50) |
1.54 (0.47–5.02) |
0.98 (0.94–1.03) |
| Laboratory† | ||||||
| Leukocytes <3.6 × 109 cells/L | 0.89 (0.85–0.94) | 0.61 (0.53–0.69) | 0.75 (0.69–0.81) | 0.82 (0.74–0.89) | 2.27 (1.83–2.82) | 0.18 (0.11–0.28) |
| Hemoglobin <13 g/dL | 0.10 (0.06–0.15) | 0.84 (0.77–0.90) | 0.45 (0.30–0.60) | 0.42 (0.36–0.48) | 0.63 (0.35–1.12) | 1.07 (0.98–1.17) |
| Platelets <100 × 109/L | 0.53 (0.45–0.60) | 0.67 (0.59–0.75) | 0.67 (0.59–0.75) | 0.52 (0.45–0.59) | 1.58 (1.20–2.08) | 0.71 (0.58–0.87) |
| Neutrophils <1.4 × 109 cells/L | 0.45 (0.37–0.52) | 0.73 (0.66–0.81) | 0.68 (0.60–0.77) | 0.51 (0.44–0.58) | 1.67 (1.21–2.31) | 0.76 (0.64–0.89) |
| Neutrophils >5.9 × 109 cells/L | 0 | 0.95 (0.91–0.99) | 0 | 0.42 (0.37–0.48) | 0 | 1.05 (1.01–1.10) |
| Lymphocytes <0.9 × 109 cells/L | 0.81 (0.75–0.86) | 0.63 (0.55–0.71) | 0.74 (0.68–0.80) | 0.71 (0.63–0.80) | 2.17 (1.73–2.74) | 0.31 (0.22–0.43) |
| Creatinine >105 μmol/L | 0.03 (0.01–0.06) | 0.98 (0.97–1.00) | 0.75 (0.45–1.00) | 0.44 (0.38–0.50) | 2.31 (0.47–11.39) | 0.98 (0.95–1.01) |
| Alanine aminotransferase >54 U/L | 0.21 (0.15–0.27) | 0.73 (0.66–0.81) | 0.50 (0.38–0.62) | 0.41 (0.35–0.47) | 0.77 (0.51–1.15) | 1.09 (0.96–1.23) |
| Aspartate aminotransferase >41 U/L |
0.57 (0.50–0.64) |
0.60 (0.52–0.69) |
0.65 (0.57- 0.73) |
0.52 (0.44–0.60) |
1.44 (1.13–1.85) |
0.71 (0.57–0.88) |
| Combinations | ||||||
| Any GI symptom (nausea, vomiting, diarrhea, abdominal pain) | 0.82 (0.77–0.88) | 0.37 (0.29–0.45) | 0.63 (0.57–0.69) | 0.62 (0.51–0.72) | 1.31 (1.13–1.51) | 0.48 (0.32–0.70) |
| Any GI symptom + lymphopenia | 0.66 (0.59–0.73) | 0.76 (0.68–0.83) | 0.78 (0.71–0.85) | 0.63 (0.56–0.71) | 2.71 (1.98–3.72) | 0.45 (0.35–0.56) |
| Rash + conjunctivitis | 0.02 (0.01–0.04) | 0.93 (0.89–0.98) | 0.31 (0.06–0.56) | 0.42 (0.37–0.48) | 0.34 (0.11–1.09) | 1.04 (0.99–1.10) |
| Documented fever + rash | 0.15 (0.10–0.20) | 0.92 (0.87–0.96) | 0.70 (0.56–0.85) | 0.45 (0.40–0.51) | 1.82 (0.93–3.55) | 0.93 (0.86–1.00) |
| Documented fever + rash + any GI symptom + lymphopenia | 0.01 (0.06–0.15) | 0.96 (0.92–0.99) | 0.76 (0.59–0.93) | 0.45 (0.39–0.51) | 2.44 (1.003–5.95) | 0.93 (0.88–0.99) |
| Documented fever + rash + any GI symptom | 0.14 (0.09–0.19) | 0.96 (0.92–0.99) | 0.80 (0.66–0.94) | 0.46 (0.40–0.52) | 3.09 (1.30–7.34) | 0.90 (0.84–0.97) |
| Documented fever + rash + lymphopenia | 0.12 (0.07–0.17) | 0.94 (0.90–0.98) | 0.72 (0.56–0.89) | 0.45 (0.39–0.51) | 2.03 (0.93–4.40) | 0.94 (0.87–1.00) |
| Documented fever + lymphopenia | 0.51 (0.44–0.59) | 0.84 (0.77–0.90) | 0.80 (0.73–0.88) | 0.57 (0.50–0.64) | 3.16 (2.10–4.75) | 0.58 (0.50–0.69) |
| Documented fever + thrombocytopenia | 0.33 (0.26–0.40) | 0.88 (0.83–0.94) | 0.78 (0.69–0.88) | 0.50 (0.44–0.57) | 2.74 (1.66–4.56) | 0.76 (0.68–0.86) |
| Documented fever + lymphopenia + thrombocytopenia | 0.30 (0.23–0.37) | 0.94 (0.90–0.98) | 0.87 (0.78–0.95) | 0.51 (0.45–0.57) | 5.11 (2.51–10.38) | 0.74 (0.67–0.82) |
| Documented fever + rash, with >1 of arthralgia, myalgia, headache, conjunctivitis | 0.14 (0.09–0.19) | 0.93 (0.89–0.98) | 0.74 (0.59–0.88) | 0.73 (0.40–0.52) | 2.14 (1.03–4.43) | 0.92 (0.85–0.99) |
*GI, gastrointestinal; LRN, negative likelihood ratio; LRP, positive likelihood ratio; NPV, negative predictive value; PPV, positive predictive value. †Reference values: leukocytes, 3.6–9.3 × 109/L; hemoglobin, 11.0–15.0 g/dL; platelets, 170–420 ×109/L); neutrophils, 1.40–5.90 × 109/L; lymphocytes, 0.90–3.30 × 109/L; creatinine, 40–75 μmol/L; urea, 2.9–9.3 mmol/L;alanine aminotransferase, 14–54 U/L; aspartate aminotransferase, 15–41 U/L.