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. Author manuscript; available in PMC: 2018 Feb 10.
Published in final edited form as: Paediatr Respir Rev. 2017 Feb 15;25:43–57. doi: 10.1016/j.prrv.2016.12.006

Table 1.

Principal findings of instruments aimed at evaluating the severity of bronchiolitis

Instrument References of studies that used the instrument Measured characteristics Scoring Where the instrument’s items originated Assessment of the items for Reliability Validity Usability
Respiratory distress index score (RDI). (Alario, A.J. et al.) [20]. [20]
  • -

    Color

  • -

    Wheezing

  • -

    Accessory muscle use

  • -

    Flaring

  • -

    Grunting

  • -

    Distressfulness

 Clinical impressions with regard to each of the six variables were coded on separate, continuous 12-cm lines that were calibrated to represent increasing degrees of severity. The distance along the line to the marked point was measured, and the total for all six variables was summed. Findings of respiratory distress previously shown to be important in the evaluation of children with LTRIa
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Inter-rater agreement. For any variable on the RDI, there was no greater than 3 cm of discordance on the12-cm line between investigators. The weighted percentage agreement ranged from 90% to 98%, and Kwb ranged from 0.60 to 0.72.[20] Not assessed Not assessed
A modified score of Wang et al. (Beck R. et al) [21]. [21]
  • -

    Wheezing (0–3)

  • -

    Retractions (0–3)

  • -

    Oxygen saturation (0–3)

  • -

    Respiratory rate (0–3)

  • -

    Heart rate (0–3)

 Score (0–15) with higher scores indicating more severe disease Adapted from a previous score
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Not assessed Not assessed Not assessed
Scoring system. (Bentur, L. et al.) [22]. [22]
  • -

    Respiratory rate (0–2)

  • -

    Wheezing (0–2)

  • -

    Retraction (0–2)

  • -

    General condition (0–2)

  • -

    Oxygen saturation (0–2)

 Score (0–10) with increasing severity receiving a higher score. The scoring system is based on those used in past studies.
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Not assessed Not assessed Not assessed
Clinical score (Bentur, L. et al.) [14]. [14]
  • -

    Heart rate (0–1)

  • -

    Respiratory rate (0–1)

  • -

    Dyspnea (0–1)

  • -

    Accessory muscle use (0–1)

  • -

    Wheezing (0–1)

 Score (0–5) with increasing severity receiving a higher score Not stated
  • -

    Endorsement frequency: yes

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: yes Lack of ambiguity: no

 Not assessed Not assessed Not assessed
Clinical scoring system. (Berger I. et al) [23]. [23]
  • -

    Accessory muscle use (0–3)

  • -

    Wheezing (0–3)

  • -

    Respiratory rate (0–3)

 Score (0–9) with higher scores indicating greater severity of bronchiolitis Previous scale
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Not assessed Not assessed Not assessed
Pulmonary index (Bierman CW. et al) [24]. [24]
  • -

    Respiratory rate (0–3)

  • -

    Wheezing score (0–3)

  • -

    Inspiratory/Ex piratory ratio (0–3)

  • -

    Accessory respiratory muscle utilization (0–3)

 Score (0–12) where higher scores indicate more severe disease Adapted from a previous instrument
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Not assessed Not assessed Not assessed
Severity of illness scoring system. (Conrad DA. et al) [25]. [25] Nose
  • -

    Discharge (0–3)

    Throat

  • -

    Dysphagia (0–3)

  • -

    Dysphonia (0–3)

  • -

    Exudate (0–3)

    Chest

  • -

    Retractions (0–3)

  • -

    Stridor (0–3)

  • -

    Rales (0–3)

  • -

    Tubular breath sounds (0–3)

  • -

    Cough (0–3)

  • -

    Ronchi (0–3)

    Gastrointestinal tract

  • -

    Anorexia (0–3)

  • -

    Vomiting (0–3)

  • -

    Nausea (0–3)

  • -

    Diarrhea (0–3)

  • -

    Abdominal pain (0–3)

    Other

  • -

    Headache (0–3)

  • -

    Myalgias (0–3)

  • -

    Arthralgias (0–3)

  • -

    Rash (0–3)

 Score (0–60) with higher scores indicating greater severity of bronchiolitis Not stated
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Not assessed Not assessed Not assessed
The bronchiolitis score (Dabbous IA. et al) [26]. [26]
  • -

    Cyanosis (0–3)

  • -

    Activity (0–3)

  • -

    Cough (0–3)

  • -

    Respiratory rate (0–3)

  • -

    Retraction score (0–3)

  • -

    Resonance (0–3)

  • -

    Wheezing (0–3)

  • -

    Expiration/inspiration (0–3)

  • -

    Liver spleen (0–3)

 Score (0–27) with higher scores indicating greater severity of bronchiolitis Not stated
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Inter-rater agreement. overall scores on duplicate comparisons were within 1 point of each other in greater than 95% of observations.[26] Not assessed Ease of scoring was qualitatively reported as “easy to score”.
A simplified bronchiolitis score. (Dabbous, I.A. et al.) [26]. [26]
  • -

    Respiratory rate (0–3)

  • -

    Retraction score (0–3)

  • -

    Wheezing (0–3)

  • -

    Expiration/inspiration ratio (0–3)

  • -

    Liver and spleen (0–3)

 Score (0–15), with higher scores indicating more severe disease. Previous score
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Not assessed Not assessed Not assessed
Modified-Tal scoring system. (De Boeck K. et al) [27]. [27–31]
  • -

    Respiratory rate (0–3)

  • -

    Wheezing (0–3)

  • -

    Oxygen saturation (0–3)

  • -

    Accessory respiratory muscle utilization (0–3)

 Score (0–12), with higher scores indicating greater severity of bronchiolitis Adapted from a previous instrument
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Internal consistency: Cronbach alpha value: 0.70. Inter-rater agreement: Kw: 0.70 (95% CI: 0.63, 0.76).[29] Construct validity: For predicting requirement for oxygen at 12 and 24 aROCc: 0.75 (95% CI: 0.34, 1.0).[29] Not assessed
A modified Respiratory Distress Assessment Instrument (RDAI). (De Brasi, D. et al) [32]. [32]
  • -

    Wheezing (0–8)

  • -

    Retractions (0–9)

    Modification concerns lung fields location of wheezing

 Score (0–17), with higher scores indicating more severe disease Previous scale
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Not assessed Not assessed. Not assessed
Children’s Hospital of Wisconsin Respiratory Score (CHWRS). (Destino L. et al) [33]. [33]
  • -

    Breath sounds (0–3)

  • -

    Dyspnea (0–3)

  • -

    Retractions (0–3)

  • -

    Respiratory rate (0–3)

  • -

    Heart rate (0–3)

  • -

    Oxygen need (0–3)

  • -

    Activity appearance (0–3)

  • -

    Cough ability/secretions (0–3)

  • -

    Chest x-ray/lung sounds (0–3)

  • -

    Surgical status (0–3)

 Score (0–30), with higher scores indicating greater severity of bronchiolitis The score was created by a panel of local clinicians and respiratory therapists after reviewing scores in existence
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

  • -

    Responsiveness: there was a mild correlation between the change in the CHWRS and RACS after an intervention (r=0.39, p=0.04).[33]

 Inter-rater agreement: ICCd: 0.73 (95% CI: 0.60–0.82).[33] Construct validity: aROC: 0.68 with a cutoff point of 7.5 (scores >7.5 predicting admission), giving a sensitivity of 0.65 and a specificity of 0.65.[33] There was no statistically significant correlation between RDAI and LOSe (r= 0.05, p=0.61).[33] Not assessed
Clinical scoring. (Gadomski, A.M. et al.) [35]. [35, 36]
  • -

    Grunting (0–3)

  • -

    Nasal flaring (0–3)

  • -

    Supraclavicular retractions (0–3)

  • -

    Intercostal retraction (0–3)

  • -

    Chest indrawing (0–3)

  • -

    Air entry (0–3)

  • -

    Air hunger (0–3)

  • -

    Wheezing (0–3)

  • -

    General appearance (0–3)

 Not specified. Scores are missing in intermediate grades, such as 1 and 2, because these categories were omitted from the scoring instrument due to high inter-rater variability during reliability testing. Compilation of other scoring systems used in past studies
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Inter-rater agreement, the mean two-rater agreement on all items were 77% for grading of the clinical signs.[36] Construct validity: the correlation coefficients for total score versus SpO2f ranged from r=−0.31 to −0.46, p<0.001.[36] Not assessed
Severity Score. (Goh A. et al) [37]. [37]
  • -

    Respiratory rate (0–4)

  • -

    Subcostal retractions (0–3)

  • -

    Presence of crepitations (0–1)

  • -

    Presence of wheeze (0–4)

  • -

    Oxygen requirement (0–1)

  • -

    Nebulization (0–1)

  • -

    Intravenous infusion (0–1)

 Score (0–15), with higher scores indicating more severe disease. Not stated
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Not assessed Not assessed Not assessed
Respiratory Score. (Groothuis JR. et al) [38]. [38, 39]
  • -

    Oxygen saturation (0–5)

  • -

    Respiratory rate (0–5)

  • -

    Retractions, wheezing, crackles (0–5)

 The score (0–5) is the mode of the three component scores, or the mean if there is no mode. Not stated
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Not assessed Not assessed Not assessed
The Kristjansson Respiratory Score. (Kristjansson S. et al) [40]. [40]
  • -

    Respiratory rate (0–2)

  • -

    Chest recession (0–2)

  • -

    Breath sound (0–2)

  • -

    Skin color (0–2)

  • -

    General condition (0–2)

 Score (0–10), with higher scores indicating more severe disease Not stated
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Inter-rater agreement. ICC: 0.89.[41] Construct validity: There was a significant negative correlation between the Kristjansson Respiratory Score and SO2 for two observers (r =−0.75, p <0.001) and (r=−0.73, p <0.001).[41] Not assessed
The Respiratory Distress Assessment Instrument (RDAI). When used as a marker of change with respiratory rate, it is called the Respiratory Assessment Change Score (RACS). (Lowell DI. et al) [11]. [11, 33, 42–64]
  • -

    Wheezing (0–8)

  • -

    Retractions (0–9)

  • -

    Respiratory rate (included when measuring change)

 Score (0–17), with higher scores indicating more severe disease Derived from underlying pathophysiology and variables frequently used by clinicians in assessing improvement in wheezing children
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

  • -

    Responsiveness: there was a mild correlation between the change in the CHWRS and RACS after an intervention (r= 0.39, p= 0.04).[33] aROC: RDAI: 0.64 to 0.70; RACS: 0.72.[64]

 Inter-rater agreement: Kw: 0.90 for wheezing and 0.64 for retractions.[11] ICC: 0.39 (95% CI: 0.17–0.58).[33] Kw: 0.93 (95% CI: 0.89, 0.97).[45] ICC: 0.65. [48] Kw: 0.94.[52] ICC: 0.91. [60] ICC: 0.93. [64] Construct validity: The aROC for the RDAI was 0.51 being not predictive of disposition. [33] There was no statistically significant correlation between RDAI and LOS (r= 0.04, p=0.7 1)[33] The changes in work of breathing markers such as inspiratory to expiratory ratio, breath sounds, grunting, nasal flaring, and global clinical response to treatment, was consistent with the three respiratory variables used in the RAID.[11] Baseline RDAI were positively correlated with respiratory rate (r=0.38, p<0.01), and scores increased in lower oxygen saturation categories (p<0.01). Scores differed between participants who were discharged, admitted, or stayed in the EDg (p<0.001).[ 64] Not assessed
Clinical score. (Maayan C. et al) [65]. [65]
  • -

    Retractions (0–3)

  • -

    Expiratory wheezing (0–3)

 Score (0–6) with increasing severity receiving a higher score Not stated
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Not assessed Not assessed Not assessed
The W.A.R.M. Respiratory Scoring Tool. (Marks M PR. et al) [66]. [66]
  • -

    Wheezing (0–2)

  • -

    Air exchange (0–2)

  • -

    Respiratory rate (0–1)

  • -

    Muscle use/retractions (0–2)

 Score (0–7) with higher scores indicating greater severity of bronchiolitis Not stated
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Not assessed Not assessed Not assessed
Acute Bronchiolitis Severity Scale (ABSS). (Ramos Fernandez JM. et al) [10]. [10]
  • -

    Wheezing (0–4)

  • -

    Crackles (0–4)

  • -

    Respiratory effort (0–3)

  • -

    Inspiration/expiration ratio (0–2)

  • -

    Heart rate (0–2)

  • -

    Respiratory rate (0–2)

 Score (0–17) with higher scores indicating more severe disease Items were derived from underlying pathophysiology, previous scales, and discussion with local clinicians who attend patients suffering from bronchiolitis.
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Internal consistency: Cronbach alfa value: 0.83. Test-retest reliability: Kw: 0.93 Inter-rater agreement: Kw: 0.682.[10] Construct validity: The scores of the ABSS were different between patients who required ambulatory treatment, admission to the PMF, and those who required admission to the PICU.[10] Not assessed
A clinical scoring system. (Richter H. et al) [67]. [67]
  • -

    Respiratory rate

  • -

    Retractions

  • -

    Wheezing

  • -

    Oxygen saturation

  • -

    Need for IV fluids or nasogastric tube feeding

 Score not described Scoring system adapted from a previous score
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Not assessed Not assessed Not assessed
Tal scoring system. (Tal A. et al) [12]. [12, 29, 69–73]
  • -

    Respiratory rate (0–3)

  • -

    Wheezing (0–3)

  • -

    Cyanosis (0–3)

  • -

    Accessory respiratory muscle utilization (0–3)

 Score (0–12), with higher scores indicating greater severity of bronchiolitis Previous instrument
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Inter-rater agreement: the instrument showed no differences greater than one point,[12] and scores did not differ by more than 1 unit for scores less than 5.[71] Kw: 0.72 (95% CI: 0.63–0.83).[29] Internal consistency: (Cronbach alpha value): 0.66.[29] Construct validity: For predicting requirement for oxygen at 12 and 24 hrs aROC: 0.69 (95% CI: 0.13, 1.0).[29] Not assessed
Severity score. (Wainwright C. et al) [74]. [74]
  • -

    Respiratory-effort score (1–3)

  • -

    Oxygen saturation (0–2)

  • -

    Respiratory rate (0–2)

 Score (1–7) where higher scores indicate more severe disease Not stated
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Not assessed Not assessed Not assessed
A bronchiolitis severity assessment tool. (Walsh P. et al) [75]. [75, 76]
  • -

    Retractions

  • -

    Heart rate

  • -

    Age

  • -

    Dehydration

 Score not described. The assessment tool is an ordinal regression model Derived from a ordinal regression model
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Inter-rater agreement. Kw: 0.676, p < 0.0001.[76] Construct validity: The model predicted admission with 91 % sensitivity and 83% specificity in a validation cohort.[75] Not assessed
The Wang Respiratory Score. (Wang EE. et al) [13]. [13, 41, 77–80]
  • -

    Respiratory rate (0–3)

  • -

    Wheezing (0–3)

  • -

    Retraction (0–3)

  • -

    General condition (0–3)

 Score (0–12), with higher scores indicating greater severity of bronchiolitis Adapted from a previous instrument
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Inter-rater agreement. ICC: 099. [41] The rater agreement for the four clinical signs of the score ranged from Kw 0.25–0.48.[13] Construct validity: There was a significant negative correlation between the Wang Respiratory Score and SpO2 for two observers (r= −0.41, p=0.04) and (r=−0.43, p=0.03).[41] There was a poor correlation between total score and oximetry (r=−0.04).[13] Not assessed
The pediatric component of the Comprehensive Severity Index (CSI). (Willson, D.F. et al.) [81]. [81] Digestive
  • -

    Difficult feeding (0–3)

  • -

    Vomiting (0–3)

    Lab-ABG’s

  • -

    PO2/FiO2 ratio (0–4)

  • -

    O2 sat/FiO2 ratio (0–4)

  • -

    Highest PH (0–4)

  • -

    Lowest PO2 (1–2)

  • -

    Lowest pH (0–4)

  • -

    Highest PCO2 (0–4)

    Lab-Heme

  • -

    Highest WBC (0–4)

  • -

    Highest Bands (0–3)

  • -

    Lowest WBC (0–4)

    Neurology

  • -

    Mental Status (0–4)

    Radiology

  • -

    Hyperexpansion of Lungs (0–1)

    Respiratory

  • -

    Cyanosis (0–1)

  • -

    Sputum/secretions (0–3)

  • -

    Apnea/Dyspnea (0–1)

  • -

    Rales (0–3)

  • -

    Breath Sounds (0–4)

  • -

    Nasal Flaring (0–3)

  • -

    Retractions (0–4)

  • -

    Expiratory grunt (0–3)

  • -

    Wheezing (1–2)

  • -

    O2 saturation (0–4)

    Vital signs

  • -

    Highest RR (1–4)

  • -

    Lowest Temp (oral) (0–4)

  • -

    Highest Temp (oral) (0–3)

 Not specified CSI is a severity scoring system based on physiologic and laboratory measures of the patient’s clinical status and is age and disease specific. The pediatric CSI is a modification of the adult CSI. Expert physician panels from the participating institutions developed explicit pediatric severity criteria to rate severity for each ICD-9-Clinical Modification (CM) diagnosis code or groups of similar codes. These criteria are based on objective clinical or historical findings (ie, physiologic signs and symptoms of a disease and not on treatment).
  • -

    Endorsement frequency: no

  • -

    Restrictions in range: no

  • -

    Comprehensiveness: no

  • -

    Lack of ambiguity: no

 Not assessed Construct validity: Maximum CSI had the highest correlation coefficient with hospital costs (r2= 0.42) and lengths of stay (r2= 0.41). CSI scores also correlated well with measures of resource utilization in subgroups of bronchiolitis patients with comorbidities or other risk factors for severe disease.[81] Not assessed
a

LTRI: lower tract respiratory infection

b

Kw: weighted kappa

c

aROC: area under the ROC curve

d

ICC: intraclass correlation coefficient

e

LOS: length of stay

f

SpO2: oxygen saturation level

g

ED: emergency department