Development and validation of a predictive model of failed stepping-down of inhaled corticosteroids in adult asthmatics

Figures & data

Table 1 Baseline demographics and clinical characteristics of patients included in analyses

	Total (n=126)	Success of stepping-down (n=97)	Failure of stepping-down (n=29)	P-value
Age, yr	54.3±16.3	55.4±17.1	51.3±13.9	0.11
Sex, % female	73	68	90	0.03
Duration of asthma, yr	9.6±13.1	11.7±14.5	3.7±3.8	0.07
BMI	22.4±3.7	22.5±3.6	22.3±4.0	0.78
Cough predominant, %	33	26	55	0.02
Rhinitis/rhinosinusitis, %	15	11	30	0.002
Family history of asthma	35	31	50	0.12
Smoking status
Smoker/ex-smoker/no	8/23/95	7/20/70	1/3/25	0.46
IgE, IU/L	367±972	450±1,119	133±141	0.16
FEV1, %predicted	94.0±19.4	92.6±19.9	97.9±18.0	0.48
SOA	5.3±2.6	5.2±2.5	5.6±2.9	0.93
Phlegm grade	5.8±1.2	5.9±1.1	5.4±1.6	0.07
Adherence	0.85±0.24	0.90±0.16	0.88±0.19	0.21
Dosage of ICSsa				0.24
High dose, n (%)	22 (18)	17 (18)	5 (20)	0.97
Moderate dose, n (%)	67 (53)	55 (57)	12 (40)	0.15
Low dose, n (%)	37 (28)	25 (25)	12 (40)	0.11
Type of ICSs				0.44
Fluticasone, n (%)	72 (57)	56 (58)	16 (55)	0.81
Budesonide, n (%)	47 (37)	37 (38)	10 (34)	0.72
Beclomethasone HFA, n (%)	7 (6)	4 (4)	3 (11)	0.20
Combination therapy, n (%)	93 (73)	61 (63)	22 (76)	0.20
Types of LABAs				0.12
Salmeterol, n (%)	57 (61)	44 (72)	13 (59)	0.96
Formoterol, n (%)	26 (39)	17 (28)	9 (41)	0.45
Other antiasthmatics
Antileukotrienes, n (%)	11 (9)	7 (7)	4 (14)	0.28
Nasal steroids, n (%)	9 (8)	5 (5)	4 (14)	0.21

Notes: Unless otherwise stated values are mean ± SD.

a ICS dose and dose equivalence were classified according to the BTS guidelines³⁰ as 1) high dose (≥800 μg/d beclomethasone (BDP) equivalent); 2) moderate dose (400–800 μg/d BDP); 3) low dose (<400 μg/d BDP) and dose equivalence for BDP:budesonide at a 1:1 ratio and BDP:fluticasone at a 2:1 ratio.

Abbreviations: BMI, body mass index; FEV₁, forced expiratory volume in 1 second; HFA, hydrofluoroalkane; ICSs, inhaled corticosteroids; LABAs, long-acting bronchodilator agonists; SOA, severity of asthma; yr, years.

Table 2 Factors associated with successful stepping-down of ICSs and creating a scoring scheme: multiple logistic regression analysis

Variables	Coefficient	SE	OR (95% CI)	P-value	Scoring score for individual
Sex: female	−0.76	0.90	0.47 (0.08–2.72)	0.40	0
Duration of asthma: 7 years or more	−0.12	0.68	0.89 (0.23–3.35)	0.86	0
Type: cough predominant	−0.59	0.66	0.55 (0.15–2.01)	0.37	0
Family history of asthma: yes	0.68	0.65	1.97 (0.55–7.09)	0.30	0
Phlegm grade: 5 or less (occasionally)	−1.13	8.50	0.32 (0.09–0.98)	0.04	1
Comorbidity: rhinitis/rhinosinusitis	−1.30	3.81	1.27 (0.07–0.97)	0.04	1

Abbreviations: CI, confidence interval; ICSs, inhaled corticosteroids; OR, odds ratio; SE, standard error.

Figure 1 Time to treatment failure during stepping-down of ICSs.

Notes: The cumulative percentage and hazard ratio of patients with failed stepping-down of ICSs was estimated by using the Kaplan–Meier method (A) and Nelson–Aalen plot (B). In cumulative percentage of failed stepping-down of ICSs using Kaplan–Meier method, solid line – score 0, hatched line – score 1, and broken line – score 2 are displayed in prediction score for failed stepping-down of ICSs.
Abbreviation: ICSs, inhaled corticosteroids.

British Thoracic Society/Scottish Intercollegiate Guidelines NetworkGuideline on the management of asthmaThorax200358Suppl I1192

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