Summary of findings 1. Summary of included studies.
| Study ID | Ethnicity or race | GA and PNA | Sample size and number of paired results | TcB device and site of measurement | TSB measurement and time interval | Indication for bilirubin | Phototherapy use | Cutoff values | Accuracy outcomes |
| Bhutta 1991 | Pakistani newborns, race not specified | GA: >34 weeks (term and late preterm) PNA: not reported |
63 newborns; 100 paired comparisons | JM 101: forehead | Photometry; ≤ 2 hours | Clinical jaundice | No prior phototherapy | TcB index of 17 to detect TSB > 12.5 mg/dL | Sensitivity 87%, specificity 53%, NPV 86.5%, PPV 55.6% |
| Bilgen 1998 | Turkish newborns, race not specified | GA: > 37 weeks (term) PNA: 1–5 days |
96 newborns; 96 paired comparisons | JM 101; forehead | Direct spectrophotometry; ≤ 30 minutes | Clinical jaundice | No prior phototherapy | TcB 13 mg/dL to detect TSB 12.9 mg/dL | Sensitivity 100%, specificity 55%, NPV 100%, PPV 32% |
| Christo 1988 | South Indian | GA: >37 weeks (term) and 32–37 weeks (preterm) PNA: not reported |
138 newborns; 138 paired comparisons | JM 101; forehead and sternum (average of the 2 readings) | Spectrophotometry; 30 minutes | Infants from whom blood specimen was drawn for bilirubin or other reasons | No prior phototherapy | TcB 18 mg/dL to detect TSB > 13 mg/dL | Sensitivity 95%, specificity 83%, NPV 98%, PPV 69% |
| Karrar 1989 | Saudi newborns (Riyadh, Saudi Arabia) | GA: > 37 weeks (term) PNA: 4–10 days |
155 newborns; 155 paired comparisons | JM 101; forehead | American optical bilirubinometer; time interval not reported (probably 30 minutes) | Clinical jaundice | No prior phototherapy | TcB index of 21 to detect TSB ≥ 12.5 mg/dL | Sensitivity 74.0%, specificity 90%, NPV 88.0%, PPV 78.0% |
| Maisels 1982 | White newborns | GA: > 37 weeks (term) PNA: not reported |
157 newborns; 292 paired comparisons | JM 101; forehead and sternum | Diazo method; ≤ 30 minutes | Routine bilirubin measurement except in 11 infants (measurement obtained on clinical grounds) | No prior phototherapy | Forehead TcB index of 24 to detect TSB > 12.9 mg/dL. Sternum TcB index of 23 to detect TSB > 12.9 mg/dL |
Forehead TcB: sensitivity 100%, specificity 97%, NPV 100%, PPV 58%. Sternum TcB: sensitivity 100%, specificity 96%, NPV 100%, PPV 44% |
| Schumacher 1985 | "Caucasian" (presumed white) | GA: > 36 weeks; PNA: 1–5 days |
106 newborns; 106 paired comparisons | JM 101; sternum | Direct spectrophotometry; ≤ 30 minutes | Clinical jaundice | No prior phototherapy | TcB 20 mg/dL to detect TSB > 12.9 mg/dL | Sensitivity 94%, specificity 77.5%, NPV 99%, PPV 44% |
| Taha 1984 | Saudi newborns | GA: > 37 weeks (term) PNA: 3–12 days |
68 newborns; 120 paired comparisons | JM 101; forehead | Direct spectrophotometry; near simultaneous measurements | Clinical jaundice | No prior phototherapy | TcB index of 22.5 to detect TSB > 12.9 mg/dL | Sensitivity 69%, specificity 92%, NPV 95%, PPV 58% |
| Wong 2002 | Mostly white, 6 non‐white | GA > 31 weeks (term and preterm) PNA: not reported |
64 newborns; 64 paired comparisons | JM 102 and BiliChek; forehead | Photometry; ≤ 30 minutes | Clinical jaundice | No prior phototherapy | JM 102: TcB > 170 μmol/L (10 mg/dL) to detect TSB > 250 μmol/L (14.6 mg/dL) Bilichek: TcB > 150 μmol/L (8.8 mg/dL) to detect TSB > 250 μmol/L (14.6 mg/dL) |
JM 102: sensitivity 100%, specificity 32%, NPV 100%, PPV 35% Bilichek: sensitivity 100%, specificity 21.3%, NPV 100%, PPV 31.5% |
| Bental 2009 | Mixed (Ashkenazi and Sephardic Ethiopian) at Natanya Hospital, Israel | GA: ≥ 35 weeks (late preterm) and > 37 weeks (term) PNA: ≤ 7 days |
628 newborns; 1091 paired comparisons | JM 103; forehead and sternum (mean from 2 sites was calculated) | Colorimetric method; ≤ 90 minutes | Clinical jaundice | No prior phototherapy | TcB > P75 to predict TSB > P95 on the nomogram | At 24–48 hours: sensitivity 83.3%, specificity 77.5%, NPV 99.2%, PPV 12.2% At 48–72 hours: sensitivity 100%, specificity 75.9%, NPV 100%, PPV 4.5% |
| Kitsommat 2013 | Asian newborns (not specified) | GA term and late preterm PNA: 5–14 days |
405 newborns; 455 paired comparisons | JM‐103 forehead | Diazo method; ≤ 30 minutes | Clinical jaundice | No prior phototherapy, or at least 24 hours since phototherapy | TcB 204 μmol/L (11.9 mg/dL) to detect | Sensitivity 96.0%, specificity 58.0%, NPV 97.4%, PPV 45.3% |
| Lam 2008 | Chinese newborns (Hong Kong) | GA: > 35 weeks (term and late preterm) PNA: 3–7 days |
113 newborns; 113 paired comparisons | JM 103; forehead and sternum | Spectrophotometry; ≤ 5 minutes | Clinical jaundice | No prior phototherapy | TcB 230 μmol/L (13.5 mg/dL) and 298 μmol/L (17.7mg/dL) to predict TSB > 250 μmol/L (14.6 mg/dL) | Sensitivity 100%, specificity 100%, NPV 100%, PPV 100% (for both cutoff values) |
| Mendoza‐Chuctaya 2021 | Cusco, Peru | GA: ≥ 37 weeks (term) PNA: not reported |
123 newborns; 123 paired comparisons | JM 103; forehead and sternum | TSB measurement method not reported; samples obtained 30 minutes | Clinical jaundice | No prior phototherapy | TcB > P95 and > P75 to predict TSB > P95 on the nomogram | Sternum TcB ≥ P95: sensitivity 100%, specificity 80%, NPV 100%, PPV 81% Sternum TcB ≥ P75: sensitivity 100%, specificity 26%, NPV 100%, PPV 54% Forehead TcB ≥ P95: sensitivity 93%, specificity 89%, NPV 94%, PPV 88% Forehead TcB ≥ P75: sensitivity 100%, specificity 33%, NPV 100%, PPV 56% |
| Yaser 2014 | South African newborns | GA: 24–34 weeks (preterm) PNA: < 8 days |
122 newborns; 122 paired comparisons | JM 103; forehead, sternum, interscapular area | TSB measurement method not reported; time interval not reported | Clinical jaundice | No prior phototherapy | Single cutoff values not reported as phototherapy initiation was based on unit phototherapy guidelines ("photo line") | Forehead: sensitivity 80.6%, specificity 87.3%, NPV 78.7%, PPV 88.5% Chest: sensitivity 70.2%, specificity 96.4%, NPV 72.6%, PPV 95.9% Interscapular region: sensitivity 94.0%, specificity 72.7%, NPV 90.9%, PPV 80.8% |
| Boo 2007 | Malay, Chinese, and Indian newborns | GA: 37 weeks (term) PNA: not reported |
345 newborns; 345 paired comparisons | BiliChek; forehead and sternum | Direct spectrophotometry; ≤ 30 minutes | Clinical jaundice | No prior phototherapy | Forehead: TcB 250 μmol/L (14.9 mg/dL) to detect TSB of 300 μmol/L (17.5 mg/dL). Sternum: TcB 200 μmol/L (11.7 mg/dL) to detect TSB 300 μmol/L (17.5 mg/dL) |
Forehead: sensitivity 100%, specificity 39.2%, NPV 100%, PPV 38.5%. Sternum: sensitivity 100%, specificity 33.6%, NPV 100%, PPV 36.4% |
| Campbell 2011 | White, Black Asian, Indian, Latino (Canada) | GA: ≥ 35 weeks (late preterm and term) PNA: not reported |
430 newborns; 430 paired comparisons | BiliChek; forehead | Direct spectrophotometry; ≤ 30 minutes | Clinical jaundice | No prior phototherapy | TcB 180 μmol/L (10.5 mg/dL) to detect TSB > 200 μmol/L (11.7 mg/dL) TcB 200 μmol/L to detect TSB 250 μmol/L (14.6 mg/dL) |
TcB 180 μmol/L to detect TSB 250 μmol/L: sensitivity 96%, specificity 55%, NPV 96%, PPV 64% TcB 200 μmol/L to detect TSB 250 μmol/L: sensitivity 96%, specificity 57%, NPV 97%, PPV 34% |
| Hemmati 2013 | Iranian newborns | GA: ≥ 35 weeks (term and late preterm, most infants) and ≤ 35 weeks (preterm, 5 infants) PNA: 1–15 days |
560 newborns; paired comparisons not reported | BiliChek; forehead | Spectrophotometry and Diazo method; time interval reported | Clinical jaundice | No prior phototherapy | TcB 15 mg/dL 256 μmol/L) to detect TSB > 15mg/dL (256 μmol/L) | Sensitivity 96.6%, specificity 99.0% NPV 99.8% PPV 95.7% |
| Karon 2008 | 146 "Caucasian" (presumed white) 19 Asian, 9 Hispanic, 3 African American | GA: > 32 weeks (term and late preterm) PNA: 1–4 days |
177 newborns; 177 paired comparisons | BiliChek; forehead | Diazo and vitros method; 30 minutes | Clinical jaundice | No prior phototherapy | High or high‐intermediate TcB to predict high or high‐intermediate TSB | Diazo: sensitivity 98%, specificity 40%, NPV 98%, PPV 44% Vitros: sensitivity 94%, specificity 55%, NPV 90%, PPV 68% |
| Knupfer 2001 | 128 "Caucasian" (presumed white), 7 Asian | GA: 23‐36 weeks (preterm) PNA: 2–6 days |
135 newborns; 400 paired comparisons | BiliChek; forehead | Diazo method; time interval not reported | Indication for bilirubin measurement not reported | No prior phototherapy | TcB to correctly identify various threshold for phototherapy; specific cutoff values not reported | Sensitivity 88%, specificity 89.1%, NPV 97.4%, PPV 62.2% |
| Kolman 2007 | Hispanic newborns (Phoenix, AZ) | GA: > 35 weeks (term and late preterm) PNA: 0–144 hours |
192 newborns; 192 paired comparisons | BiliChek; forehead | Diazo method; ≤ 30 minutes | Universal bilirubin screening | No prior phototherapy | TcB > P75 to predict TSB > P95 on the nomogram | Sensitivity 100%, specificity 66%, NPV 100%, PPV 16% |
| Neocleous 2014 | White newborns | GA: ≥ 37 weeks (term) PNA: 24– 96 hours |
222 newborns; 368 paired comparisons | BiliChek; forehead | Direct spectrophotometry; ≤ 20 minutes | Clinical jaundice | Prior use of phototherapy not reported | TcB 207 μmol/L (12 mg/dL) to detect TSB 205 μmol/L (12 mg/dL) TcB 265 μmol/L (15 mg/dL) to detect TSB 240 μmol/L (14 mg/dL) |
TcB 207 μmol/L to detect TSB 205 μmol/L: sensitivity 95.4%, specificity 18.6%, NPV 55.2%, PPV 79.4% (at 24 hours) TcB 265 μmol/L to detect TSB 240 μmol/L: sensitivity 94.2%, specificity 22.5%. NPV 73.8%, PPV 62.5% (at 48 hours) |
| Samanta 2004 | Race/population not reported | GA: ≥ 33 weeks (preterm) and ≥ 37 weeks (term) PNA: 1–11 days |
300 newborns; 300 paired comparisons | BiliChek; site of measurement not reported | Diazo method; near simultaneous measurements with TcB | Clinical jaundice | No prior phototherapy | TcB 195 μmol/L (11.4 mg/dL) to detect TSB 250 μmol/L (14.6 mg/dL) | Sensitivity 91% specificity 66%, NPV 96% PPV 42% |
| Bertini 2008 | Italian/white (Florence, Italy) | GA: > 32 weeks (preterm and term) PNA: not reported |
241 newborns; 241 paired comparisons | Bilitest BB 77; forehead | Spectrophotometry; 10 minutes | Clinical jaundice | No prior phototherapy | TcB 13 mg/dL to detect TSB 15 mg/dL | Sensitivity 85.7%, specificity 97.8%, NPV 99.1%, PPV 70.6% |
| Ercan 2018 | Turkish newborns, race not specified | GA: ≥ 35 weeks (term and late preterm) PNA: 2–30 days |
218 newborns; 271 paired comparisons | JH20‐1C; forehead | Spectrophotometry ≤ 10 minutes | Clinical jaundice | No prior phototherapy | TcB 205 μmol/L (12 mg/dL) to detect TSB ≥ 222 μmol/L (13 mg/dL) | Sensitivity 95.9%, specificity 59.4%, NPV 90%, PPV 77.7%; |
GA: gestational age; NPV: negative predictive value; PNA: postnatal age; PPV: positive predictive value; Px: xth percentile TcB: transcutaneous bilirubin; TSB: total serum bilirubin.