Incidence and Intensity of Catastrophic Health-care Expenditure for Type 2 Diabetes Mellitus Care in Iran: Determinants and Inequality

Figures & data

Table 1 Descriptive Characteristics of Type 2 Diabetes Mellitus Patients by Incidence of CHE

Variable	Number (%)	Incidence of CHE (95%CI) at the 40% of CTP Threshold
Observation	1065 (100)	11.4 (9.5–13.4)
Gender
Male	310 (29.1)	9.3 (6.6– 3.2)
Female	755 (70.9)	12.2 (10.0–14.7)
Age
22–55	366 (34.4)	7.6 (5.3–10.9)
56–65	419 (39.3)	12.2 (9.3–15.7)
66–86	280 (26.3)	15.0 (11.2–19.7)
Household size
1–2	418 (39.2)	16.3 (12.8–19.8)
3–4	512 (48.1)	8.9 (6.7–11.8)
≥5	135 (12.7)	5.9 (2.9–11.5)
Education
Illiterate or primary education	750 (70.4)	10.9 (8.8 –13.8)
Junior or senior education	100 (9.4)	14.0 (8.4 –22.4)
University or higher	215 (20.2)	11.6 (7.9–16.7)
Marital status
Never married	22 (2.1)	31.8 (14.9–55.3)
Married	967 (90.8)	11.1 (9.2–13.2)
Divorced/widow	76 (7.1)	9.2 (4.3–18.3)
Occupation
Housewife or unemployed	715 (67.1)	11.1 (8.9–13.5)
Retired	165 (15.5)	13.3 (8.9–19.5)
Self-employed	138 (13.0)	10.1 (6.0–16.5)
Employed	47 (4.4)	12.8 (5.6–26.2)
Socioeconomic status
Q1 (the poorest)	276 (25.9)	16.7 (12.6–21.5)
Q2	270 (25.4)	12.9 (9.4–17.5)
Q3	246 (23.1)	8.1 (5.2–12.3)
Q4 (the richest)	273 (25.6)	7.3 (4.7–11.1)
Place of living
Isfahan	386 (36.2)	5.7 (3.8–8.5)
Sanandaj	305 (28.7)	10.5 (7.5–14.4)
Sabzevar	374 (35.1)	17.9 (14.3–22.1)
Health insurance
Iranian health insurance	430 (40.5)	11.8 (9.1–15.3)
Armed forces health insurance	76 (7.1)	15.7 (9.1–26.0)
Social security insurance	485 (45.7)	10.3 (7.9–13.3)
Others^a	71 (6.7)	11.2 (5.6–21.2)
Duration of Diabetes (years)
≤5	348 (32.7)	10.6 (7.8–14.3)
5–10	339 (31.8)	10.6 (7.7–14.4)
>10	378 (35.5)	12.7 (9.7–16.4)
Inpatient services
No	917 (86.1)	9.8 (8.0–11.9)
Yes	148 (13.9)	20.9 (15.7–28.3)
Complication
No	283 (26.6)	11.3 (8.1–15.5)
Yes	782 (73.4)	11.4 (9.3–13.8)

Notes: ^aNo health insurance, Imam Khomeini health insurance, etc.

Abbreviations: CTP, capacity to pay; CHE, catastrophic health-care expenditure.

Table 2 Descriptive Statistics of Type of Household Expenditure by Socioeconomic Status

	Q1	Q2	Q3	Q4
Household total expenditure per capita (IRRs)	18,028,990	17,850,740	17,149,590	18,427,840
Household food expenditure per capita as % of total expenditure per capita	52.6	23.8	50.8	50.3
Household nonsubsistence spending per capita as % of total expenditure per capita	47.4	76.2	49.2	49.7
Household diabetes related OOP per capita as % of total expenditure per capita	7.5	8.1	8.2	7.3
Household OOP per capita as % of total expenditure per capita	13.8	14.7	25.0	14.7

Notes: The value of US$1 at the time of the study was equal to 128,986 Iranian Rials (IRRs).

Table 3 Incidence and Intensity of CHE for Type 2 Diabetes Mellitus Care by Socioeconomic Status

	Thresholds of Capacity to Pay
	10%	20%	30%	40%
Incidence of CHE
Q1	60.5	33.3	22.1	16.7
Q2	59.2	31.5	18.5	12.9
Q3	52.8	25.2	13.4	8.1
Q4	57.1	25.2	11.7	7.3
Overall	57.5	28.9	16.6	11.4
Overshoot %
Q1	0.13.4	8.6	5.7	3.7
Q2	0.13.5	8.7	6.2	4.5
Q3	0.09.6	5.4	3.3	2.0
Q4	0.09.0	4.9	3.0	2.0
Overall	3.1	11.4	6.9	4.6
Mean positive overshoot %
Q1	22.2	25.8	26.1	22.4
Q2	22.8	27.8	33.3	34.9
Q3	18.3	21.8	24.4	25.5
Q4	15.8	19.6	25.6	27.8
Overall	27.4	19.9	24.1	27.7

Notes: Quartile 1 (Q1) is the poorest and quartile 4 (Q4) is the richest.

Abbreviation: CHE, catastrophic health-care expenditure.

Table 4 Results of Multivariate Logistic Regression of Determinants of Incidence of CHE for Type 2 Diabetes Mellitus at the 40% of CTP Threshold, Iran, 2019

Variables	Crude OR (95%CI)	Adjusted OR (95%CI)
Gender
Male (ref.)	1	1
Female	1.34 (0.86–2.08)*	1.73 (1.06–2.81)**
Age
22–55 (ref.)	1	1
56–65	1.67 (1.03–2.7)**	1.80 (1.04–3.13)**
66–86	2.13 (1.28–3.53)***	2.27 (1.25–4.13)***
Household size
1–2	1	1
3–4	0.51 (0.34–0.77)***	0.70 (0.44–1.12)*
≥5	0.33 (0.15–0.71)***	0.52 (0.23–1.18)*
Education
Illiterate or primary education	1	1
Junior or senior education	1.32 (0.72–2.46)*	1.68 (0.85–3.30)*
University or higher	1.07 (0.66–1.72)*	1.56 (0.81–2.99)*
Marital status
Never married	1	1
Married	0.26 (0.11–0.66)***	0.25 (0.09–0.67)***
Divorced/widow	0.22 (0.06–0.71)***	0.26 (0.07–0.95)**
Occupation
Housewife or unemployed	1	1
Retired	1.24 (0.74–2.05)*	1.11 (0.62–2.00)*
Self-employed	0.91 (0.49–1.65)*	0.97 (0.50–1.86)*
Employed by an organization	1.17 (0.48–2.86)*	1.52 (0.53–4.39)*
Socioeconomic status
Q1 (the poorest)	1	1
Q2	0.72 (0.46–1.19)*	0.71 (0.42–1.18)*
Q3	0.44 (0.25–0.77)***	0.44 (0.24–0.80)***
Q4 (the richest)	0.39 (0.23–0.69)***	0.32 (0.17–0.63)***
Health insurance
Iranian health insurance	1	1
Armed forces health insurance	1.39 (0.70–2.75)*	1.34 (0.64–2.84)*
Social security insurance	0.85 (0.56–1.29)*	0.94 (0.60–1.46)*
Other^a	0.94 (0.42–2.08)*	0.95 (0.41–2.20)*
Place of living
Isfahan	1	1
Sanandaj	1.93 (1.11–3.41)***	2.06 (1.10–3.84)**
Sabzevar	3.61 (2.17–5.98)***	3.93 (2.22–6.97)***
Duration of diabetes (years)
≤5	1	1
5–10	0.99 (0.61–1.62)*	1.14 (0.67–1.92)*
>10	1.22 (0.77–1.92)*	1.26 (0.75–2.12)*
Inpatient services
No	1	1
Yes	2.43 (1.54–3.82)***	2.33 (1.42–3.80)***
Complications
No	1	1
Yes	1.01 (0.65–1.54)*	1.07 (0.67–1.71)*

Notes: ^aNo health insurance, Imam Khomeini health insurance, etc. *p>0.05; **p<0.05; ***p<0.01.

Abbreviations: CI, confidence interval; OR, odds ratio.

Table 5 Results of Relative Concentration Index and Slope Index of Inequality for Incidence of CHE Among Patients with Type 2 Diabetes Mellitus

CTP Thresholds	Relative Concentration Index (95%CI)	Slope Index of Inequality (95%CI)
10%	−0.04 (−0.10 to 0.02)*	0.06 (−0.04 to 0.16)*
20%	−0.09 (−0.16 to −0.02)**	0.12 (0.02 to 0.21)**
30%	−0.16 (−0.25 to −0.07)**	0.14 (0.06 to 0.22)**
40%	−0.20 (−0.31 to −0.10)**	0.12 (0.05 to 0.18)**

Notes: *p>0.05; **p<0.05.

Abbreviation: CTP, capacity to pay.

Figure 1 Concentration curve for incidence of CHE for type 2 diabetic care in different CTP thresholds.

Table 6 Results of Decomposition Analysis of CHE Among Type 2 Diabetes Mellitus Patients

Variable	Elasticity	Concentration x	Contribution
			Absolute	%	Summed
Gender
Male (ref.)
Female	0.264	−0.022	−0.007	3.2	3.2
Age
22–55 (ref.)
56–65	0.158	0.003	0.001	−0.3
66–86	0.145	−0.001	0.000	0.1	−0.2
Household size
1–2 (ref.)
3–4	−0.112	0.018	−0.002	1.1
≥5	−0.057	0.051	−0.003	1.6	2.7
Education
Illiterate or primary education (ref.)
Junior or senior education	0.032	0.157	0.006	−2.7
University or higher	0.061	0.429	0.029	−14.2	−17.0
Marital status
Never married (ref.)
Married	−0.856	0.008	−0.008	3.8
Divorced/widow	−0.063	0.001	0.000	0.0	3.8
Occupation
Housewife or unemployed (ref.)
Retired	0.011	0.187	0.002	−1.1
Self-employed	−0.002	0.049	0.000	0.1
Employed by an organization	0.011	0.514	0.007	−3.2	−4.2
Socioeconomic status
Q1 (the poorest) (ref.)
Q2	−0.057	−0.228	0.015	−7.1
Q3	−0.126	0.257	−0.037	17.8
Q4 (the richest)	−0.189	0.744	−0.159	77.3	88.0
Health insurance
Iranian health insurance (ref.)
Armed forces health insurance	0.014	0.073	0.001	−0.6
Social security insurance	−0.016	0.027	0.000	0.2
Others^a	−0.002	−0.303	0.001	−0.3	−0.6
Place of living
Isfahan (ref.)
Sanandaj	0.136	0.074	0.011	−5.5
Sabzevar	0.325	−0.024	−0.009	4.2	−1.3
Duration of diabetes (years)
≤5 (ref.)
5–10	−0.051	0.039	−0.002	1.1
>10	−0.025	−0.048	0.001	−0.6	0.4
Inpatient services
No (ref.)
Yes	0.080	−0.051	−0.005	2.249	2.500
Complication
No (ref.)
Yes	0.032	−0.018	−0.001	0.317	0.320
Explained total			−0.159		77.6
Unexplained total			−0.046		22.4
Sum			−0.205		100

Notes: ^aNo health insurance, Imam Khomeini health insurance, etc.