Adherence to COPD treatment in Turkey and Saudi Arabia: results of the ADCARE study

Figures & data

Table 1 Demographics of the study population

Variable	Saudi Arabia n=206	Turkey n=199	Overall n=405
Gender, n (%)
Count	206	199	405
Men	155 (75.2)	175 (87.9)	330 (81.5)
Women	51 (24.8)	24 (12.1)	75 (18.5)
Age, n (%)
Count	206	199	405
40–49 years	6 (2.9)	15 (7.5)	21 (5.2)
50–59 years	42 (20.4)	50 (25.1)	92 (22.7)
≥60 years	158 (76.7)	134 (67.3)	292 (72.1)
Body mass index, n (%)
Count	200	197	397
Underweight	2 (1.0)	11 (5.6)	13 (3.3)
Normal weight	58 (29.0)	78 (39.6)	136 (34.3)
Overweight	66 (33.0)	64 (32.5)	130 (32.8)
Obese	74 (37.0)	44 (22.3)	118 (29.7)
Educational level, n (%)
Count	200	183	383
No high school	146 (73.0)	115 (62.8)	261 (68.2)
High school graduate	43 (21.5)	45 (24.6)	88 (23.0)
College graduate	11 (5.5)	23 (12.6)	34 (8.9)
Health system coverage, n (%)
Count	198	198	396
Social security/public	182 (91.9)	188 (95.0)	370 (93.4)
Private/insured	10 (5.1)	2 (1.0)	12 (3.0)
Not insured	6 (3.0)	1 (0.5)	7 (1.8)
Other	0	7 (3.5)	7 (1.8)
Smoking status, n (%)
Count	206	199	405
Non-smoker	67 (32.5)	11 (5.5)	78 (19.3)
Past-smoker	97 (47.1)	144 (72.4)	241 (59.5)
Smoker	42 (20.4)	44 (22.1)	86 (21.2)
Pack-years, n (%)
Count	130	166	296
<10 pack-years	5 (3.9)	5 (3.0)	10 (3.4)
≥10 pack-years	125 (96.2)	161 (97.0)	286 (96.6)
Number of comorbidities, n (%)
Count	206	199	405
No comorbidity	40 (19.4)	79 (39.7)	119 (29.4)
At least one comorbidity	166 (80.6)	120 (60.3)	286 (70.6)

Note: Sociodemographics of the study population: distribution of patients, by age, gender, country, body mass index, health system coverage, level of education, smoking status, and presence of comorbidities.

Table 2 Disease characteristics

Variable	Saudi Arabia n=206	Turkey n=199	Overall n=405
Age at symptom onset (years)
Count	201	199	400
Mean (±SD)	51.6 (±12.1)	52.9 (±10.9)	52.3 (±11.5)
Disease duration (years)
Count	202	199	401
Mean (±SD)	11.7 (±10.0)	8.3 (±7.5)	10.0 (±9.0)
Time between symptom onset and diagnosis (years)
Count	199	196	395
Mean (±SD)	3.4 (±5.5)	2.4 (±5.9)	2.9 (±5.7)
Exacerbations in the last 12 months, n (%)
Count	199	199	398
No	77 (38.7)	112 (56.3)	189 (47.5)
Yes	122 (61.3)	87 (43.7)	209 (52.5)
CAT score, n (%)
Count	197	195	392
<10	13 (6.6)	41 (21.0)	54 (13.8)
10–15	32 (16.2)	45 (23.1)	77 (19.6)
>15	152 (77.2)	109 (55.9)	261 (66.6)
MRC dyspnea scale, n (%)
Count	194	197	391
MRC =1	13 (6.7)	22 (11.2)	35 (9.0)
MRC >1	181 (93.3)	175 (88.8)	356 (91.1)
EQ-5D-3L utility values
Count	197	199	396
Mean (±SD)	0.52 (±0.37)	0.66 (±0.27)	0.59 (±0.33)
EQ-VAS score
Count	205	198	403
Mean (±SD)	70.3 (±14.8)	59.9 (±18.7)	65.2 (±17.6)
HADS anxiety score, n (%)
Count	195	197	392
<8	96 (49.2)	128 (65.0)	224 (57.1)
8–10	61 (31.3)	35 (17.8)	96 (24.5)
>10	38 (19.5)	34 (17.3)	72 (18.4)
HADS depression score, n (%)
Count	193	197	390
<8	70 (36.3)	109 (55.3)	179 (45.9)
8–10	51 (26.4)	51 (25.9)	102 (26.2)
>10	72 (37.3)	37 (18.8)	109 (28.0)

Notes: Disease characteristics of the study population. An exacerbation was defined as a hospitalization or emergency room visit.

Abbreviations: CAT, COPD Assessment Test; EQ-5D-3L, 3-level EuroQol Five-Dimension questionnaire; EQ-VAS, EuroQol Visual Analog Scale; HADS, Hospital Anxiety and Depression Scale; MRC, Medical Research Council.

Table 3 Disease management

Variable	Saudi Arabia n=206	Turkey n=199	Overall n=405
Lung function test in the last 6 months, n (%)
Count	198	194	392
No	106 (53.5)	16 (8.3)	122 (31.1)
Yes	92 (46.5)	178 (91.8)	270 (68.9)
Last value of FEV1, n (%)
Count	84	175	259
<30%	2 (2.4)	20 (11.4)	22 (8.5)
30%–50%	22 (26.2)	64 (36.6)	86 (33.2)
>50%	60 (71.4)	91 (52.0)	151 (58.3)
Last value of FVC, n (%)
Count	84	174	258
<50%	11 (13.1)	29 (16.7)	40 (15.5)
50%–70%	30 (35.7)	64 (36.8)	94 (36.4)
>70%	43 (51.2)	81 (46.6)	124 (48.1)
Oxygen therapy use in the last 6 months, n (%)
Count	195	180	375
No	98 (50.3)	113 (62.8)	211 (56.3)
Yes	97 (49.7)	67 (37.2)	164 (43.7)
Treatment class, n (%)
Count	206	199	405
ICS/LABA/LAMA	156 (75.7)	151 (75.9)	307 (75.8)
ICS/LABA or ICS/LAMA	36 (17.5)	34 (17.1)	70 (17.3)
LAMA or LABA	8 (3.9)	10 (5.0)	18 (4.4)
SAMA or SABA	5 (2.4)	3 (1.5)	8 (2.0)
Other	1 (0.5)	1 (0.5)	2 (0.5)
Number of maintenance treatments (%)
Count	206	199	405
One treatment	25 (12.1)	19 (9.6)	44 (10.9)
Two treatments	81 (39.3)	87 (43.7)	168 (41.5)
More than two treatments	100 (48.5)	93 (46.7)	193 (47.7)
Mean (±SD)	2.6 (±1.1)	2.6 (±1.0)	2.6 (±1.1)
Frequency of maintenance treatment, n (%)
Count	205	199	404
Once a day or less	9 (4.4)	7 (3.5)	16 (4.0)
Twice a day	178 (86.8)	135 (67.8)	313 (77.5)
More than twice a day	18 (8.8)	57 (28.6)	75 (18.6)
Type of inhalation device, n (%)
Metered-dose inhaler	51 (24.8)	64 (32.2)	115 (28.4)
Dry powder inhaler	177 (85.9)	183 (92.0)	360 (88.9)
Nebulizer	22 (10.7)	27 (13.6)	49 (12.1)
Other	71 (34.5)	51 (25.6)	122 (30.1)

Notes: Disease management characteristics of the study population. The treatment class “other” includes ICS alone, and ICS and methylxanthine. The type of inhalation device “other” includes capsule, diskus, handihaler, inhaler capsule, injection, mask, nasal, nasal pillow, oral, spray, subcutaneous, subcutaneous injection, subcutanous, tablet, turbuhaler, vaccine, and nasal spray.

Abbreviations: FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; ICS, inhaled corticosteroid; LABA, long-acting beta agonist; LAMA, long-acting muscarinic antagonist; SABA, short-acting beta agonist; SAMA, short-acting muscarinic antagonist.

Table 4 Adherence to treatment

Variable	Saudi Arabia n=206	Turkey n=199	Overall n=405	p-value
Morisky score*, n (%)
Count	190	196	405
Mean (±SD)	4.6 (±2.4)	6.2 (±1.8)	5.4 (±2.3)	<0.0001
<6 (low)	122 (64.2)	68 (34.7)	190 (49.2)	<0.0001
6 to <8 (medium)	46 (24.2)	73 (37.2)	119 (30.8)
=8 (high)	22 (11.6)	55 (28.1)	77 (20.0)

Notes: Adherence to treatment for the overall study population and by country, measured using the MMAS-8. The p-values were calculated using the χ²-test for the MMAS-8 categories and the Kruskal–Wallis test for the MMAS-8 mean score.

* The MMAS (8-item) content, names, and trademarks are protected by the US copyright and trademark laws. Permission for use of the scale and its coding is required. A license agreement is available from Donald E Morisky, ScD, ScM, MSPH,14725 NE 20th St Bellevue, WA 98007, USA; [e-mail].

Abbreviation: MMAS-8, 8-Item Morisky Medication Adherence Survey.

Table 5 Association between adherence to treatment, impact of COPD on health status, and quality of life

Variable		Low adherence (MMAS-8 <6) n=190	Medium or high adherence (MMAS-8 ≥6) n=196	p-value
CAT score, n (%)	Count	186	190	0.0008
	<10	15 (8.1%)	38 (20.0%)
	10–15	32 (17.2%)	41 (21.6%)
	>15	139 (74.7%)	111 (58.4%)
EQ-5D-3L utility values	Count	183	194	<0.0001
	Mean (±SD)	0.54 (±0.35)	0.64 (±0.30)
EQ-VAS score	Count	190	194	0.4623
	Mean (±SD)	63.8 (±16.5)	65.0 (±18.2)

Notes: Analysis of the relationship between the impact of COPD on health status, measured via the CAT; or quality of life (measured using the EQ-5D-3L) and represented by both the EQ-5D-3L utility value and the EQ-VAS score; and adherence to treatment, measured using the MMAS-8. The p-values were calculated using the Kruskal–Wallis test for the continuous variables (EQ-5D-3L and EQ-VAS) and the χ² for the categorical variables (CAT score categories).

Abbreviations: CAT, COPD Assessment Test; EQ-5D-3L, 3-level EuroQol Five-Dimension questionnaire; EQ-VAS, EuroQol Visual Analog Scale; MMAS-8, 8-item Modified Morisky Medication Adherence Scale.

Figure 1 Multivariate analysis: predictors of non-adherence to COPD treatment.

Notes: Multivariate regression analysis on 355 patients: 170 with low (MMAS-8 <6) adherence to treatment and 185 with medium or high (MMAS-8 ≥6) adherence to treatment (low adherence versus medium/high adherence). *p-value of the Wald Chi-Square test from the logistic regression model.
Abbreviations: HADS, Hospital Anxiety and Depression Scale; MMAS-8, 8-item Morisky Medication Adherence Scale.

Figure 2 Association between treatment adherence and CAT score.

Notes: Adjusted analysis (by country, age, and gender) of the association between adherence to treatment and the impact of COPD on health status, measured by the CAT: analysis on 307 patients: 207 with a CAT score of >15 and 100 with a CAT score of ≤15 (>15 versus ≤15). *p-value of the Wald Chi-Square test from the logistic regression model.
Abbreviation: CAT, COPD Assessment Test.

Data availability

Editors can seek information from the corresponding author regarding whether anonymized patient level data can be made available.