InterVA-4 as a public health tool for measuring HIV/AIDS mortality: a validation study from five African countries

Figures & data

Figure 1 Participating Alpha Network sites, showing numbers of deaths with verbal autopsies, by HIV status.

Table 1 Numbers of adult deaths (n=17,560) and proportions assigned by InterVA-4 as HIV/AIDS related, by age, sex, time period, and site, according to HIV status

		HIV-negative test before death, at:				HIV-positive on the basis of:
		0–11 months	12–23 months	24–59 months	Overall	Positive test and positive VA	Positive test, not VA	No test, positive VA	Prev. negative test, positive VA	Overall	HIV status unknown
Overall	Deaths	860	516	530	1,906	1,010	1,983	2,204	130	5,327	10,327
	% HIV/AIDS	8.4	9.4	12.8	9.9	45.8	36.7	43.4	43.0	41.4	15.4
15–49 years	Deaths	314	266	282	862	719	1,627	1,465	67	3,878	5,414
	% HIV/AIDS	16.1	13.9	20.1	16.7	51.2	39.3	49.0	55.1	45.4	23.8
50–64 years	Deaths	186	86	95	367	89	235	204	18	546	1,570
	% HIV/AIDS	6.8	7.5	8.2	7.3	37.4	32.6	45.4	48.1	38.7	12.8
65+ years	Deaths	360	164	153	677	202	121	535	45	903	3,343
	% HIV/AIDS	2.6	3.2	2.0	2.6	30.4	10.7	27.1	22.8	25.4	3.0
Male	Deaths	439	288	286	1,013	416	831	1,020	71	2,338	4,935
	% HIV/AIDS	5.1	7.3	6.4	6.1	39.9	27.9	38.0	39.9	34.8	12.4
Female	Deaths	421	228	244	893	594	1,152	1,184	59	2,989	5,392
	% HIV/AIDS	12.0	12.1	20.3	14.3	50.0	43.1	48.0	46.6	46.5	18.2
Pre-2002	Deaths	110	78	45	233	49	374	326	8	757	1,953
	% HIV/AIDS	24.6	18.1	26.5	22.8	70.1	58.8	53.0	85.1	57.3	20.6
2002–07	Deaths	299	200	253	752	545	1,173	1,199	59	2,976	6,338
	% HIV/AIDS	10.9	12.4	15.7	12.9	51.6	36.1	47.4	55.0	43.9	15.7
2008 on	Deaths	451	238	232	921	416	436	679	63	1,594	2,036
	% HIV/AIDS	2.9	4.1	6.9	4.2	35.5	19.5	31.7	26.3	29.1	9.3
Karonga	Deaths	96	27	17	140	43	14	199	2	258	932
	% HIV/AIDS	4.2	3.3	0	3.5	27.5	0	67.9	0	57.0	15.5
Kisesa	Deaths	97	127	141	365	68	224	90	11	393	914
	% HIV/AIDS	17.1	11.9	11.5	13.1	91.1	40.3	84.2	72.7	60.1	20.4
Manicaland	Deaths	60	60	84	204	–	639	–	–	639	186
	% HIV/AIDS	31.6	29.6	38.4	33.8	–	58.1	–	–	58.1	57.8
Masaka	Deaths	129	22	24	175	–	101	–	–	101	134
	% HIV/AIDS	27.0	21.0	7.8	23.6	–	57.5	–	–	57.5	34.6
Rakai	Deaths	78	77	67	222	507	230	921	76	1,734	1,424
	% HIV/AIDS	3.1	5.4	7.6	5.3	49.0	18.8	41.3	45.6	40.8	6.8
uMkhanyakude	Deaths	400	203	197	800	392	775	994	41	2,202	6,737
	% HIV/AIDS	1.7	2.9	6.2	3.1	35.8	21.3	36.7	32.2	31.0	15.0

The InterVA-4 model was ‘blinded’ to the HIV sero-status data, only taking into account a history or diagnosis of HIV/AIDS if reported in the VA interview.

Table 2 Specificities for InterVA-4 assignment of HIV/AIDS-related deaths, based on people with a negative HIV test result in the 5-year period before death

		Specificity	95% confidence interval
Overall		90.1	88.7–91.4
Age group	15–49 years	83.3	80.6–85.6
	50–64 years	92.7	89.5–94.9
	65+ years	97.4	95.9–98.4
Sex	Male	94.0	92.3–95.3
	Female	85.7	83.3–87.9
Period	1990–2002	77.2	71.4–82.1
	2002–2007	87.1	84.5–89.3
	2008–2011	95.8	94.3–96.9
Study site	Karonga	96.5	92.0–98.5
	Kisesa	86.9	83.0–90.0
	Manicaland	66.2	59.5–72.3
	Masaka	87.0	81.2–91.2
	Rakai	94.8	91.0–97.0
	uMkhanyakude	95.9	94.3–97.1

Figure 2 Cause-specific mortality rate ratios for HIV-positive: HIV-negative deaths, based on Poisson multivariate modelling of mortality rates, adjusted for age group, sex, and study site, showing 95% confidence intervals (CIs). The all-cause adjusted mortality rate ratio was 29.0 (95% CI 27.1–31.0), represented by the vertical axis.

Table 3 InterVA-4 causes of death, cause-specific mortality fractions, and adjusted mortality ratios by known HIV status for 1,739 deaths in 1,161,688 HIV-negative person-years observed and 2,890 deaths in 75,110 HIV-positive person-years observed

	Cause-specific mortality fraction (%)		Mortality rate per 1,000 per year
WHO VA cause of death by InterVA-4	HIV negative	HIV positive	HIV negative	HIV positive	Mortality rate ratio
01.02 Acute respiratory infections, including pneumonia	4.16	6.33	0.06	2.44	39.1
01.03 HIV/AIDS-related death	10.60	38.89	0.16	14.96	94.3
01.04 Diarrhoeal diseases	1.07	0.36	0.02	0.14	8.6
01.05 Malaria	3.17	1.95	0.05	0.75	15.8
01.07 Meningitis and encephalitis	1.12	1.33	0.02	0.51	30.5
01.09 Pulmonary tuberculosis	11.54	28.71	0.17	11.05	63.9
01.99 Other and unspecified infectious disease	1.68	1.54	0.03	0.59	23.5
02.01 Oral neoplasms	0.49	0.37	0.01	0.14	19.2
02.02 Digestive neoplasms	3.92	1.98	0.06	0.76	13.0
02.03 Respiratory neoplasms	2.58	0.60	0.04	0.23	6.0
02.04 Breast neoplasms female	0.51	0.19	0.01	0.07	9.6
02.06 Reproductive neoplasms female	1.61	0.90	0.02	0.34	14.3
02.99 Other and unspecified neoplasms	1.85	0.56	0.03	0.21	7.7
03.01 Severe anaemia	0.80	0.11	0.01	0.04	3.7
03.02 Severe malnutrition	0.35	0.41	0.01	0.16	29.7
03.03 Diabetes mellitus	3.75	0.73	0.06	0.28	5.0
04.01 Acute cardiac disease	1.62	0.40	0.02	0.15	6.4
04.02 Stroke	4.73	0.40	0.07	0.15	2.2
04.99 Other and unspecified cardiac disease	5.31	0.69	0.08	0.27	3.4
05.01 Chronic obstructive pulmonary disease	2.82	0.17	0.04	0.07	1.6
05.02 Asthma	1.59	0.49	0.02	0.19	8.0
06.01 Acute abdomen	6.38	2.79	0.10	1.07	11.2
98 Other and unspecified non-communicable disease	2.45	0.44	0.04	0.17	4.6
12.01 Road traffic accident	2.71	0.47	0.04	0.18	4.4
12.08 Intentional self-harm	0.99	0.14	0.01	0.05	3.6
12.09 Assault	6.18	1.29	0.09	0.50	5.4
12.99 Other and unspecified external cause of death	1.57	0.23	0.02	0.09	3.8
09.03 Pregnancy-induced hypertension	0.38	0.14	0.01	0.05	9.1
09.04 Obstetric haemorrhage	1.09	0.15	0.02	0.06	3.6
09.06 Pregnancy-related sepsis	0.28	0.17	0.00	0.07	15.7
09.99 Other and unspecified maternal cause of death	0.37	0.33	0.01	0.13	22.9
99 Indeterminate	12.31	6.74	0.18	2.59	14.1
All causes	100	100	1.50	38.48	25.7