Table 5.

Factors associated with poor control of asthma among children, adolescents, and adults in multilevel analysis

		Overall population	HICs	UMICs	LMICs and LICs
Children
Severity of symptoms*
	Mild	2·55 (2·22–2·93)	2·76 (2·24–3·40)	2·42 (1·93–3·03)	2·17 (1·53–3·07)
	Severe	6·48 (5·61–7·47)	7·72 (6·10–9·76)	5·83 (4·69–7·24)	5·55 (3·91–7·89)
Country income category†
	UMIC	0·92 (0·56–1·52)	..	..	..
	LMIC and LIC	2·33 (1·32–4·14)	..	..	..
Asthma management plan‡		1·16 (1·03–1·30)	1·01 (0·85–1·21)	1·15 (0·95–1·39)	1·56 (1·17–2·08)
Inhaled medicine§
	SABA	2·01 (1·76–2·30)	2·03 (1·63–2·51)	1·99 (1·61–2·45)	2·13 (1·52–2·97)
	LABA	1·02 (1·02–1·31)	1·24 (0·76–2·01)	1·05 (0·61–1·82)	0·77 (0·41–1·42)
	Corticosteroids	1·16 (1·02–1·31)	1·10 (0·91–1·33)	1·35 (1·12–1·62)	0·81 (0·54–1·24)
	Corticosteroids and LABA	1·24 (1·07–1·43)	1·20 (0·96–1·52)	1·31 (0·96–1·44)	1·08 (0·67–1·74)
Oral medicine§
	LTRA	1·18 (1·02–1·37)	1·22 (0·95–1·56)	1·18 (0·96–1·44)	1·02 (0·60–1·75)
	Corticosteroids	1·80 (1·57–2·08)	2·14 (1·73–2·65)	1·44 (1·16–1·79)	2·24 (1·47–3·42)
	SABA	1·61 (1·40–1·84)	1·60 (1·29–1·98)	1·79 (1·47–2·17)	1·10 (0·66–1·84)
	Theophylline	0·97 (0·75–1·27)	0·97 (0·60–1·57)	1·06 (0·69–1·63)	0·85 (0·49–1·49)
Adolescents
Severity of symptoms*
	Mild	1·65 (1·49–1·83)	1·56 (1·33–1·83)	1·79 (1·52–2·10)	1·59 (1·22–2·08)
	Severe	3·82 (3·46–4·21)	3·80 (3·24–4·46)	3·88 (3·35–4·48)	4·03 (3·15–5·15)
Country income category†
	UMIC	2·33 (1·30–4·16)	..	..	..
	LMIC and LIC	3·46 (1·83–6·54)	..	..	..
Asthma management plan‡		1·32 (1·21–1·43)	1·38 (1·21–1·57)	1·25 (1·10–1·41)	1·35 (1·10–1·64)
Inhaled medicine§
	SABA	1·95 (1·77–2·15)	2·29 (1·95–2·69)	1·65 (1·43–1·92)	2·13 (1·67–2·72)
	LABA	1·17 (1·00–1·36)	1·18 (0·93–1·51)	1·32 (1·03–1·70)	0·98 (0·67–1·43)
	Corticosteroids	1·30 (1·14–1·48)	1·15 (0·94–1·39)	1·57 (1·27–1·93)	1·17 (0·85–1·63)
	Corticosteroids and LABA	0·93 (0·81–1·07)	1·02 (0·84–1·25)	0·77 (0·61–0·97)	0·95 (0·67–1·34)
Oral medicine§
	LTRA	1·18 (1·02–1·36)	1·37 (1·08–1·74)	1·04 (0·84–1·28)	1·51 (1·01–2·28)
	Corticosteroids	1·38 (1·17–1·63)	1·68 (1·28–1·22)	1·22 (0·96–1·56)	1·41 (0·94–2·10)
	SABA	1·39 (1·24–1·57)	1·53 (1·28–1·82)	1·28 (1·05–1·57)	1·38 (0·99–1·93)
	Theophylline	1·14 (0·91–1·41)	0·77 (0·52–1·31)	1·34 (0·96–1·88)	1·15 (0·72–1·83)
Adults
Severity of symptoms*
	Mild	1·88 (1·60–2·22)	2·06 (1·60–2·66)	2·21 (1·66–2·95)	1·18 (0·85–1·65)
	Severe	5·70 (4·88–6·66)	5·60 (4·31–7·27)	6·40 (4·90–8·35)	4·27 (3·13–5·83)
Country income category†
	UMIC	1·43 (0·80–2·55)	..	..	..
	LMIC and LIC	4·86 (2·55–9·26)	..	..	..
Asthma management plan‡		1·24 (1·09–1·41)	1·01 (0·81–1·25)	1·17 (0·95–1·44)	1·70 (1·31–2·21)
Inhaled medicine§
	SABA	1·71 (1·48–1·98)	1·19 (0·93–1·52)	2·22 (1·73–2·85)	2·09 (1·54–2·83)
	LABA	1·80 (1·46–2·21)	1·50 (1·03–2·19)	2·28 (1·71–3·06)	1·25 (0·61–2·55)
	Corticosteroids	1·34 (1·13–1·60)	1·42 (1·08–1·87)	1·66 (1·27–2·16)	0·84 (0·45–1·58)
	Corticosteroids and LABA	1·24 (1·06–1·46)	1·51 (1·17–1·95)	1·40 (1·06–1·84)	1·01 (0·70–1·47)
Oral medicine§
	LTRA	1·37 (1·08–1·74)	0·96 (0·60–1·54)	1·64 (1·21–2·23)	1·23 (0·52–2·92)
	Corticosteroids	1·23 (0·98–1·55)	2·56 (1·73–3·78)	0·85 (0·63–1·15)	0·96 (0·39–2·36)
	SABA	1·84 (1·55–2·20)	2·31 (1·73–3·08)	1·81 (1·39–2·35)	1·80 (1·10–2·95)
	Theophylline	1·31 (0·97–1·75)	0·68 (0·40–1·16)	1·60 (1·04–2·47)	4·12 (1·34–12·7)

Data are odds ratio (95% CI). Associations were adjusted for sex, age, country income category (high-income countries as the reference), and having an asthma management plan at the first level, school at the second level, and centre at the third level of the model. HIC=high-income country. UMIC=upper-middle-income country. LMIC=lower-middle-income country. LIC=low-income country. SABA=short-acting β2 agonist. LABA=long-acting β2 agonist. LTRA=leukotriene receptor antagonist. Reference categories:

^*asymptomatic asthma;

^†high-income countries;

^‡no asthma management plan;

^§not receiving the specific medication.