Development of a clinical prediction score for recurrent wheezing following acute lower respiratory tract infection in children

Table 1 Baseline characteristics of the study population by recurrent wheezing status, n (%)

Characteristics/risk factor	Recurrent wheezing (n = 52)	No recurrent wheezing (n = 228)	P value
Age (months), mean ± SD	31.2 ± 2.3	30.7 ± 1.1	0.843
Male	30 (57.7)	124 (54.4)	0.758
Preterm	4 (7.7)	27 (11.8)	0.472
Low birth weight	5 (9.6)	33 (14.5)	0.501
Delivery by C/S	24 (46.2)	126 (55.3)	0.281
Urban	37 (71.2)	171 (75.0)	0.599
Underlying disease	22 (42.3)	64 (28.1)	0.066
Thalassemia disease	6 (14.5)	8 (3.5)	0.028
G6PD deficiency	2 (3.9)	3 (1.3)	0.233
Allergic rhinitis	12 (23.1)	21 (9.2)	0.009
Atopic dermatitis	8 (15.4)	31 (13.6)	0.824
Food or drug allergy	6 (11.5)	13 (5.7)	0.136
Exposure smoking during pregnancy	7 (13.5)	19 (8.3)	0.288
Exposure smoking	13 (25.0)	41 (18.0)	0.248
First degree related asthma	5 (9.6)	5 (2.2)	0.022
Day care attending	36 (69.2)	134 (57.8)	0.208
Multiple URTI	32 (61.5)	121 (53.1)	0.284
Multiple LRTI	31 (59.6)	48 (21.1)	< 0.001
Eosinophilia (AEC ≥ 500 cell/mm2)	9 (25.7)	4 (3.9)	0.001
Pets	10 (19.2)	39 (17.1)	0.238
RSV infection	19 (36.5)	98 (43.0)	0.438

URTI: Upper respiratory tract infection; LRTI: Lower respiratory tract infection; AEC: Absolute eosinophil count; RSV: Respiratory syncytial virus.

Table 2 Univariable logistic regression analysis of risk factors for recurrent wheezing

Risk factor	Odd ratio	95%CI	P value
Thalassemia disease	3.59	1.19-10.83	0.023
Allergic rhinitis	2.96	1.35-6.49	0.007
Food or drug allergy	1.84	0.68-5.01	0.230
Maternal smoking during pregnancy	1.71	0.68-4.31	0.255
Passive smoke exposure	1.52	0.75-3.10	0.249
First-degree related family history of asthma	4.74	1.32-17.05	0.017
Day care attendance	1.58	0.83-3.00	0.166
Multiple LRTIs	5.54	2.92-10.49	< 0.001
Eosinophilia1	8.48	2.42-29.74	0.001
RSV infection	0.76	0.41-1.42	0.396

¹Eosinophilia was analyzed in 137 participants with available eosinophil count data; all other variables were analyzed in the full cohort of 280 participants.

LRTI: Lower respiratory tract infection; RSV: Respiratory syncytial virus; CI: Confidence interval.

Table 3 Multivariable logistic regression analysis of risk factors and predictors of recurrent wheezing, and assigned item scores

Predictors	OR	95%CI	P value	Coefficient	Score
Thalassemia disease	2.66	0.53-13.28	0.234	0.98	1
Allergic rhinitis	4.41	1.09-17.85	0.037	1.48	2
Food or drug allergy	3.57	0.50-25.44	0.204	1.27	1
First degree related asthma	5.25	0.48-57.36	0.174	1.65	2
Multiple LRTIs	3.83	1.51-9.73	0.005	1.34	1
Eosinophilia	5.43	1.31-22.53	0.020	1.69	2
Total score		Risk category		Recommended clinical follow-up
0-1 point		Low risk		Routine care; no follow up
2-3 point		Moderate risk		Follow-up within 6 months
4-9 point		High risk		Follow-up within 3 months

OR: Odds ratio; CI: Confidence interval; LRTI: Lower respiratory tract infection.

Table 4 Performance of the clinical score and risk classification for recurrent wheezing

Score (points)	Risk classification	PPV (95%CI)	NPV (95%CI)	Sensitivity (95%CI)	Specificity (95%CI)	PLR (95%CI)	NLR (95%CI)
0-1	Low	16.04% (11.88-21.31)	41.94% (28.36-56.85)	48.57% (31.38-66.01)	12.75% (6.96-20.81)	0.56 (0.39-0.79)	4.04 (2.21-7.36)
2-3	Moderate	48.0% (31.77-64.66)	79.46% (75.07-83.25)	34.29% (19.13-52.21)	87.25% (79.19-93.04)	2.69 (1.36-5.33)	0.75 (0.59-0.97)
4-9	High	100% (54.07-100)	77.86% (75.16-80.35)	17.14% (6.56-33.65)	100% (96.45-100)	∞ (due to 100% specificity)	0.83 (0.71-0.96)

PPV: Positive predictive value; CI: Confidence interval; NPV: Negative predictive value; PLR: Positive likelihood ratio; NLR: Negative likelihood ratio.