Percent Recovery Index Predicts Poor Asthma Control and Exacerbation in Adults

Figures & data

Figure 1 The calculation process of indices from the MBPT.

Figure 2 Primary and second outcomes. Primary outcomes: Acute exacerbation (no versus yes); ACT(2) (<19 versus ≧19); MiniAQLQ(2) - MiniAQLQ(1) (<0 versus >0). Second outcome: Cumulative number of EDHO. Independent variable: PRI(1).

Table 1 Baseline Characteristics

Subjects (n)	61
Male (n (%))	19 (31.15)
Age (year)	42.16 ± 11.73
BMI^a	24.22 (22.13, 26.2)
Exacerbation (yes)
Previous 1 year	27 (44.26)
In 3-month follow-up	22 (36.07)
Smoking status
Ex-smoker	7 (11.48)
Current-smoker	2 (3.28)
Medicine
ICS-LABA	57 (93.44)
ICS-LABA-LAMA	1 (1.64)
ICS-LAMA	1 (1.64)
ICS	2 (3.28)
Concomitant
Allergic Rhinitis	25 (40.98)
Hypertension	5 (8.20)
GERD	1 (1.64)
COPD	1 (1.64)

Notes: Data with normal distribution are presented as mean and standard deviation (); Data with abnormal distribution are presented as median (interquartile range). Categorical data are presented as n (%). ^akg·m⁻².

Abbreviations: ICS, inhaled glucocorticoid; LABA, long-term effect β2 receptor agonist; LAMA, long acting muscarinic receptor antagonist; BMI, body mass index; GERD, gastroesophageal reflux; COPD, chronic obstruct pulmonary disease.

Table 2 Comparison Between the Baseline and the 3-Month Follow-Up Visit

	Baseline	3 Months	P-value
Questionnaire score
ACT	19.61 ± 3.03	21.3 ± 2.93	0.002^a
MiniAQLQ	5.53 ± 0.8	5.89 ± 0.97	0.003^a
MBPT
PRI	41.2 (28.5, 56.3)	25 (5.3, 41.05)	1.90E-04^a
CIR	25 (22.43, 28)	20 (10.5, 23.1)	8.92E-05^a
PD20	0.6 (0.28, 1.342)	2.52 (0.6, 2.52)	6.42E-06^a
Spirometry
FEV1% predicted	81.53 ± 20.87	95.53 ± 18.34	4.23E-09^a
FEV1/FVC	86.34 ± 11.04	94.26 ± 7.84	4.47E-06^a
FEF75	59 (45.3, 69.4)	72 (56, 87.25)	3.43E-04^a
FEF50	75.79 ± 25.59	94.88 ± 28.27	1.51E-06^a
FEF25	84 (73, 104)	100 (87.25, 118.5)	1.02E-06^a
Inflammation factors
FENO	22 (16, 49)	20.5 (14, 54.25)	0.509
CaNO	2.9 (1.85, 5.35)	2.45 (1.6, 5.625)	0.303
EOS	0.145 (0.06, 0.28)	0.16 (0.1, 0.26)	0.573

Notes: Data with normal distribution are presented as mean and standard deviation (); Data with abnormal distribution are presented as median (interquartile range). ^aP<0.01.

Abbreviations: FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; FEF, forced expiratory flow.

Table 3 Collinearity Diagnostics for Logistic Regression Models

Variance Inflation Factor
Variables	Model 1	Model 2
Age	1.584	1.225
BMI	1.533	1.395
Sex	2.437	2.150
Previous exacerbation	1.709	1.518
Previous smoker	1.624	1.605
Current smoker	1.652	1.559
PRI	1.288	1.192
CIR	1.556	1.383
PD20	1.953	1.719
FEV1% predicted	63.360	3.586
FVC	28.695	NA
FEV1/FVC	2.619	1.587
FEF25	9.098	3.673
FEF50	14.653	NA
FEF75	9.217	NA

Notes: Model 1: Dependent variable ~ Age + BMI + sex + Previous exacerbation + Previous smoker + Current smoker + PRI + CIR + PD20 + FEV1% + FVC + FEV1/FVC + FEF25 + FEF50 + FEF75. Model 2: Dependent variable ~ Age + BMI + sex + Previous exacerbation + Previous smoker + Current smoker + PRI + CIR + PD20 + FEV1% + FEV1/FVC + FEF25.

Abbreviation: NA, not applicable.

Table 4 Relationships Between PRI and Clinical Outcomes

	Acute Exacerbation			Poor Asthma Control			Decrease of Life Quality			Cumulative Number of EDHO at 3 Months
	β Coefficient	OR (95% CI)	P-value	β Coefficient	OR (95% CI)	P-value	β Coefficient	OR (95% CI)	P-value	β Coefficient	OR (95% CI)	P-value
Age	0.000	1 (0.932, 1.072)	0.993	0.032	1.033 (0.948, 1.125)	0.462	0.037	1.038 (0.968, 1.114)	0.296	−0.003	−0.003 (−0.46, 0.454)	0.990
BMI	−0.032	0.969 (0.728, 1.289)	0.828	−0.012	0.988 (0.706, 1.384)	0.946	0.003	1.003 (0.774, 1.299)	0.984	0.006	0.006 (−0.008, 0.02)	0.372
Sex (Male, no. (%))	0.996	2.709 (0.157, 46.842)	0.493	2.063	7.87 (0.257, 241.101)	0.237	−0.752	0.471 (0.052, 4.286)	0.504	−0.018	−0.018 (−0.069, 0.034)	0.497
Previous exacerbation (no. (%))	3.827	0.022 (0.002, 0.285)	0.004^a	−3.268	0.038 (0.002, 0.854)	0.039^a	0.368	1.446 (0.251, 8.332)	0.680	0.502	0.502 (0.143, 0.861)	0.007^a
Ex smoker	−0.221	0.802 (0.046, 13.872)	0.879	23.098	10,743,815,148.466 (0, 0)	0.999	−1.251	0.286 (0.02, 4.035)	0.354	−0.377	0.186 (−0.386, 0.758)	0.456
Current smoker	2.612	13.628 (0.134, 1388.541)	0.268	2.119	8.324 (0.05, 1392.814)	0.417	−0.909	0.403 (0.002, 68.824)	0.729	0.186	−0.377 (−1.385, 0.631)	0.515
PRI	0.040	1.041 (1.006, 1.077)	0.023^a	0.050	1.051 (1.01, 1.094)	0.014^a	0.045	1.046 (1.011, 1.082)	0.010^a	0.005	0.005 (0, 0.009)	0.039^a
CIR	0.224	1.251 (0.985, 1.588)	0.066	−0.121	0.886 (0.73, 1.074)	0.218	−0.056	0.946 (0.833, 1.074)	0.390	0.017	0.017 (−0.005, 0.039)	0.135
PD20	−0.158	0.853 (0.223, 3.26)	0.817	0.013	1.013 (0.223, 4.611)	0.987	0.184	1.203 (0.412, 3.509)	0.736	−0.052	−0.052 (−0.265, 0.162)	0.628
FEV1% predicted	−0.008	0.992 (0.924, 1.066)	0.828	0.013	1.013 (0.935, 1.097)	0.754	0.032	1.032 (0.964, 1.105)	0.361	−0.003	−0.003 (−0.016, 0.011)	0.671
FEV1/FVC	−0.089	0.915 (0.825, 1.015)	0.093	−0.044	0.957 (0.847, 1.081)	0.478	0.028	1.028 (0.941, 1.123)	0.539	−0.016	−0.016 (−0.033, 0.002)	0.075
FEF25	0.057	1.058 (0.985, 1.137)	0.121	0.028	1.029 (0.951, 1.113)	0.477	0.009	1.009 (0.948, 1.074)	0.780	0.009	0.009 (−0.003, 0.021)	0.143

Notes: Acute exacerbation (during the follow-up of 3 months, no versus yes); Poor asthma control (ACT at 3 months, ≧19 versus <19). Decrease of life quality (MiniAQLQ at 3 months - MiniAQLQ at baseline, >0 versus <0). Age, BMI, PRI, CIR, PD20, FEV1%, FEV1/FVC and FEF25 were all collected at baseline; ^aP < 0.05.

Abbreviation: EDHO, unscheduled emergency or hospital visit.

Table 5 Relationships Between PRI and the Four Domains of MiniAQLQ

	Symptom			Environment			Emotion			Activity
	β Coefficient	OR (95% CI)	P-value	β Coefficient	OR (95% CI)	P-value	β Coefficient	OR (95% CI)	P-value	β Coefficient	OR (95% CI)	P-value
Age	0.009	0.602 (0.05, 7.239)	0.799	0.073	0.127 (0.015, 1.054)	0.023^a	0.057	2.916 (0.392, 21.721)	0.088	0.026	2.416 (0.344, 16.962)	0.337
BMI	0.041	1.009 (0.942, 1.081)	0.759	0.054	1.076 (1.01, 1.146)	0.619	−0.267	1.059 (0.992, 1.13)	0.052	−0.074	1.026 (0.973, 1.082)	0.473
Sex (Male, no. (%))	−0.507	1.042 (0.802, 1.354)	0.690	−2.066	1.055 (0.854, 1.304)	0.056	1.070	0.766 (0.585, 1.003)	0.296	0.882	0.928 (0.757, 1.138)	0.375
Previous exacerbation (no. (%))	−0.544	0.58 (0.087, 3.891)	0.575	0.822	2.274 (0.472, 10.961)	0.306	−0.034	0.966 (0.2, 4.68)	0.966	0.521	1.683 (0.42, 6.736)	0.462
Ex smoker	−1.176	0.309 (0.018, 5.414)	0.421	−2.183	0.113 (0.008, 1.69)	0.114	−0.577	0.561 (0.047, 6.755)	0.649	0.354	1.424 (0.146, 13.893)	0.761
Current smoker	−23.926	0 (0, 0)	0.999	−0.682	0.505 (0.011, 24.11)	0.729	1.560	4.758 (0.036, 626.964)	0.531	−20.136	0 (0, 0)	0.999
PRI	0.026	1.027 (1.003, 1.05)	0.025^a	0.042	1.043 (1.009, 1.079)	0.014^a	0.030	1.03 (1.002, 1.059)	0.039^a	−0.001	0.999 (0.981, 1.018)	0.921
CIR	−0.073	0.93 (0.81, 1.067)	0.301	0.025	1.025 (0.936, 1.123)	0.594	−0.055	0.946 (0.832, 1.077)	0.404	0.064	1.066 (0.966, 1.178)	0.204
PD20	0.114	1.121 (0.372, 3.378)	0.840	0.088	1.091 (0.43, 2.774)	0.854	0.223	1.25 (0.479, 3.26)	0.649	−0.210	0.81 (0.347, 1.893)	0.627
FEV1% predicted	0.083	1.086 (1.001, 1.18)	0.048^a	−0.048	0.953 (0.897, 1.013)	0.122	0.084	1.088 (1.017, 1.164)	0.014	0.047	1.048 (0.985, 1.116)	0.138
FEV1/FVC	0.010	1.01 (0.917, 1.112)	0.841	0.019	1.019 (0.942, 1.102)	0.637	−0.001	0.999 (0.922, 1.082)	0.975	0.006	1.006 (0.937, 1.079)	0.876
FEF25	−0.004	0.996 (0.934, 1.062)	0.902	0.045	1.046 (0.988, 1.107)	0.126	−0.031	0.969 (0.919, 1.022)	0.250	−0.008	0.992 (0.945, 1.042)	0.759

Notes: For all four domains of MiniAQLQ (score at 3 months - score at baseline, >0 versus <0); previous exacerbation: (during one year before enrollment, no versus yes); Age, BMI, PRI, CIR, PD20, FEV1%, FEV1/FVC and FEF25 were all collected at baseline; ^aP < 0.05.

Figure 3 Comparison of percent recovery index (PRI) between different state of asthmatics. (A) Acute exacerbations: During the follow up of 3 months (no vs yes). (B) Poor asthma control: ACT at 3 months (≧19 vs <19); (C) Decreased life quality: MiniAQLQ at 3 months - MiniAQLQ at baseline (>0: increase of MiniAQLQ vs <0: decrease of MiniAQLQ). The horizontal lines: the median. Boxes: the interquartile range (IQR; Q1–Q3). Whiskers: Q1−1.5×IQR (lower) and Q3+1.5×IQR (upper). Circle: outliers on the outside of Q1−1.5×IQR and Q3+1.5×IQR. *Outliers on the outside of Q1−3×IQR and Q3+3×IQR. ^#P<0.05 vs normal control group.