Incidence, socio-economic inequalities and determinants of catastrophic health expenditure and impoverishment for diabetes care in South Africa: a study at two public hospitals in Tshwane

Table 4 Concentration indices for catastrophic health expenditure for diabetes care

Indicator	Approach 1			Approach 2
Indicator	N	Index value	p-value	N	Index value	p-value
WHO Standard method
Catastrophic 10%	359	−0.1246	0.0002	343	−0.2299	0.0000
Catastrophic 20%	359	−0.0575	0.0220	343	−0.1128	0.0038
Catastrophic 30%	359	−0.0247	0.2403	343	−0.0933	0.0046
Catastrophic 40%	359	−0.0143	0.4274	343	− 0.0744	0.0148
Impoverished				320	− 0.0297	0.1158
Ataguba method (ƴ = 0.8)
Catastrophic head count ratio	362	−0.0518	0.0320	346	−0.1026	0.0148
Impoverished	341	−0.0413	0.0289	341	−0.0512	0.0460
Ataguba method (ƴ = 1)
Catastrophic head count ratio	361	−0.0236	0.2130	344	−0.0582	0.1176
Impoverished	341	−0.0413	0.0289	341	−0.0512	0.0460

Note: N - Number of observations. Note: Approach 1 estimates catastrophic health expenditure using health costs only, approach 2 uses health costs plus transport costs. Ataguba method (y = 0.8) - threshold varies with household expenditure. Ataguba method (y = 1) - constant threshold of 10%

ISSN: 1475-9276