Mortality of neurological disorders in Tanzania: analysis of baseline data from sample vital registration with verbal autopsy (SAVVY)

Figures & data

Figure 1. Geographic locations of 23 SAVVY districts on a map of Tanzania.

Figure 2. Age distribution of 6645 reported deaths (3509 males and 3136 females) from SAVVY districts.

Table 1. Distribution of causes of neurological death by age group.

	Age group
	<5	5–19	20–49	50+	All ages
Cerebrovascular diseases	1.4		27.7	65.7	33.0
Stroke, not specified as hemorrhage or infarction	1.4		24.6	60.8	30.3
Hypertensive encephalopathy				1.0	0.4
Sequelae of stroke, not specified as hemorrhage or infarction			3.1	2.9	1.9
Sequelae of other and unspecified cerebrovascular diseases				1.0	0.4
Epilepsy	4.2	40.9	36.9	11.8	18.4
Other generalized epilepsy and epileptic syndromes				1.0	0.4
Epilepsy, unspecified	4.2	40.9	36.9	11.8	18.4
Meningitis	34.7	22.7	10.8	4.9	16.1
Bacterial meningitis, not elsewhere classified	4.2				1.2
Meningitis due to other and unspecified causes	1.4				0.4
Meningitis, unspecified	29.2	22.7	10.8	4.9	14.6
Cerebral palsy and other paralytic syndromes	11.1	18.2	3.1	9.8	9.2
Cerebral palsy	1.4				0.4
Cerebral palsy, unspecified	8.3	13.6			3.5
Hemiplegia, unspecified				4.9	1.9
Paraplegia, unspecified		4.6	1.5	2.9	1.9
Paralytic syndrome, unspecified	1.4		1.5	2.0	1.5
Intrauterine hypoxia	25.0				6.9
Malignant and benign neoplasms of brain and CNS		9.1	7.7	1.0	3.1
Malignant neoplasm of brain			3.1		0.8
Malignant neoplasm of spinal cord, cranial nerves, and other parts of CNS		9.1	3.1	1.0	1.9
Benign neoplasm of brain and other parts of central nervous system			1.5		0.4
Congenital malformations of the nervous system	12.5		1.5		3.8
Congenital hydrocephalus	1.4				0.4
Congenital hydrocephalus, unspecified	4.2		1.5		1.5
Spina bifida	1.4				0.4
Spina bifida, unspecified	4.2				1.2
Congenital malformation of nervous system, unspecified	1.4				0.4
Other neurological disorders	4.2		6.2	2.9	3.8
Migraine				1.0	0.4
Migraine, unspecified			3.1	1.0	1.2
Polyneuropathy, unspecified (neuropathy NOS)			1.5	1.0	0.8
Hydrocephalus	4.2		1.5		1.5
Symptoms and signs involving the nervous and musculoskeletal systems	6.9	9.1	6.2	2.9	5.4
Other and unspecified symptoms and signs involving the nervous and musculoskeletal systems				1.0	0.4
Headache			6.2	2.0	2.3
Other and unspecified convulsions	6.9	9.1			2.7
Number of deaths	72	22	65	102	261

Table 2. Cause-specific mortality fraction (%) estimates of neurological disorders and epilepsy by sex, age, residency, and zone.

	Neurological disorders			Epilepsy
	Deaths	CSMF (95% CI)	MRF (95% CI)	Deaths	CSMF (95% CI)	MRF (95% CI)
Sex
Males	134	4.76 (4–5.55)	0.90 (0.70–1.16)	36	1.28 (0.86–1.69)	2.37 (1.23–4.88)
Females	127	5.27 (4.38–6.16)		13	0.54 (0.25–0.83)
Age
<5	72	4.13 (3.19–5.06)	0.71 (0.52–0.97)	3	0.17 (0–0.37)	0.23 (0.04–0.84)
5–19	22	6.25 (3.72–8.78)	1.07 (0.64–1.71)	9	2.56 (0.91–4.20)	3.45 (1.30–8.72)
20–49	65	4.72 (3.6–5.84)	0.81 (0.58–1.12)	24	1.74 (1.05–2.43)	2.35 (1.15–5.03)
50+	102	5.82 (4.72–6.91)		13	0.74 (0.34–1.14)
Residency
Rural	149	5.63 (4.75–6.50)		30	1.13 (0.73–1.54)	0.65 (0.35–1.19)
Urban	112	4.35 (3.56–5.13)	0.77 (0.60–0.99)	19	0.74 (0.41–1.07)
Zone
Western	31	4.74 (3.11–6.37)	0.75 (0.46–1.21)	7	1.07 (0.28–1.86)	1.00 (0.31–3.16)
Northern	25	3.53 (2.17–4.88)	0.56 (0.33–0.93)	3	0.42 (0–0.90)	0.40 (0.07–1.65)
Central	43	4.68 (3.31–6.04)	0.74 (0.48–1.15)	12	1.30 (0.57–2.04)	1.22 (0.46–3.45)
Southern Highlands	39	6.61 (4.60–8.61)	1.05 (0.67–1.64)	4	0.68 (0.01–1.34)	0.63 (0.14–2.37)
Eastern	43	4.8 (3.41–6.21)	0.77 (0.49–1.18)	8	0.89 (0.28–1.51)	0.84 (0.27–2.56)
Southern	33	4.65 (3.10–6.20)	0.74 (0.46–1.18)	7	0.99 (0.26–1.71)	0.92 (0.28–2.91)
Lake	47	6.27 (4.54–8.01)		8	1.07 (0.33–1.80)
Overall	261	4.99 (4.40–5.58)		49	0.94 (0.68–1.20)

Ref: Reference category; CSMF: cause-specific mortality fraction, MRF, mortality rate fraction; CI: confidence interval.

Table 3. Cause-specific mortality fraction (%) estimates of cerebrovascular disorders (95% CI) by sex, age, residency, and zone.

	Cerebrovascular diseases			Cerebrovascular diseases (50+ years)
	Deaths	CSMF (95% CI)	MRF (95% CI)	Deaths	CSMF (95% CI)	MRF (95% CI)
Sex
Males	38	1.99 (1.43–2.55)		27	2.87 (1.80–3.93)	0.58 (0.34–0.97)
Females	48	1.35 (0.92–1.78)	0.68 (0.43–1.06)	40	4.93 (3.44–6.42)
Age
<5	1	0.06 (0.00–0.17)	0.02 (0.00–0.09)
5–19	0
20–49	18	1.31 (0.71–1.91)	0.34 (0.19–0.58)
50+	67	3.82 (2.92–4.72)
Residency
Rural	35	1.32 (0.89–1.76)		29	3.42 (2.20–4.65)
Urban	51	1.98 (1.44–2.52)	1.50 (0.95–2.37)	38	4.19 (2.89–5.50)	1.23 (0.73–2.06)
Zone
Western	11	2.14 (1.10–3.17)	0.79 (0.33–1.81)	9	6.08 (2.23–9.93)	0.99 (0.37–2.47)
Northern	9	1.27 (0.44–2.09)	0.59 (0.23–1.43)	7	2.30 (0.62–3.99)	0.37 (0.12–1.00)
Central	8	0.87 (0.27–1.47)	0.41 (0.15–1.01)	6	1.68 (0.35–3.01)	0.27 (0.08–0.76)
Southern Highlands	12	2.03 (0.89–3.17)	0.95 (0.41–2.14)	10	6.54 (2.62–10.45)	1.05 (0.41–2.59)
Eastern	18	2.01 (1.09–2.93)	0.94 (0.45–1.98)	12	3.87 (1.72–6.02)	0.62 (0.26–1.48)
Southern	12	1.69 (0.74–2.64)	0.79 (0.34–1.78)	10	3.68 (1.44–5.91)	0.59 (0.23–1.46)
Lake	16	1.68 (0.70–2.67)		13	6.22 (2.94–9.49)
Overall	86	1.64 (1.30–1.99)		67	3.82 (2.92–4.72)

Ref: Reference category; CSMF: cause-specific mortality fraction; MRF: mortality rate fraction; CI: confidence interval.

Table 4. Cause-specific mortality fraction (%) estimates of meningitis disorders by sex, age, residency, and zone.

		Meningitis			Meningitis (age 0–19)
	Deaths	CSMF(95% CI)	MRF (95% CI)	Deaths	CSMF (95% CI)	MRF (95% CI)
Sex
Males	23	0.82 (0.48–1.15)	1.04 (0.54–2.04)	18	1.57 (0.85–2.29)	1.25 (0.57–2.84)
Females	19	0.79 (0.43–1.14)		12	1.26 (0.55–1.97)
Age
<5	25	1.43 (0.88–1.99)	5.02 (1.89–16.81)		1.43 (0.88–1.99)	1.01 (0.38–3.37)
5–19	5	1.42 (0.18–2.66)	4.98 (1.15–21.64)	25	1.42 (0.18–2.66)
20–49	7	0.51 (0.13–0.88)	1.78 (0.49–7.13)	5
50+	5	0.28 (0.03–0.53)
Residency
Rural	25	0.94 (0.57–1.31)		19	1.57 (0.87–2.27)
Urban	17	0.66 (0.35–0.97)	0.70 (0.35–1.35)	11	1.24 (0.51–1.97)	0.79 (0.34–1.75)
Zone
Western	5	0.76 (0.10–1.43)	0.67 (0.17–2.11)	5	1.26 (0.16–2.37)	0.58 (0.15–2.01)
Northern	4	0.56 (0.01–1.11)	0.47 (0.10–1.68)	1	0.56 (0.00–1.65)	0.25 (0.01–1.91)
Central	1	0.11 (0.00–0.32)	0.09 (0.00–0.65)	0
Southern Highlands	14	2.37 (1.14–3.60)	1.97 (0.80–5.17)	12	4.33 (1.93–6.73)	0.04 (0.02–0.03)
Eastern	5	0.56 (0.07–1.05)	0.46 (0.12–1.55)	1	0.31 (0.00–0.91)	0.14 (0.00–1.05)
Southern	4	0.56 (0.01–1.11)	0.47 (0.10–1.68)	3	1.39 (0.00–2.95)	0.64 (0.11–2.65)
Lake	9	1.20 (0.42–1.98)		8	2.18 (0.69–3.68)
Overall	42	0.80 (0.56–1.04)		30	1.43 (0.92–1.94)

Ref: Reference category; CSMF: cause-specific mortality fraction; MRF: mortality rate fraction; CI: confidence interval.

Table 5. Cause-specific mortality fraction (%) comparison of neurological disorders by study.

	Age 0–4 years		Age 15–49 years		All ages
	SAVVY	GBD	SAVVY	GBD	SAVVY	GBD
Cerebrovascular	0.02 (0.00–0.09)	0.07 (0.04–0.09)	1.20 (0.65–1.92)	1.23 (0.96–1.76)	1.64 (1.30–1.99)	3.16 (2.66–3.63)
Epilepsy	0.17 (0–0.37)	0.11 (0.08–0.14)	1.94 (1.24–2.64)	0.55 (0.43–0.69)	0.94 (0.68–1.20)	0.25 (0.22–0.30)
Meningitis	1.43 (0.88–1.99)	3.53 (2.30–6.07)	0.53 (0.16–0.91)	1.53 (1.06–2.23)	0.80 (0.56–1.04)	2.10 (1.61–2.94)
Road injuries	0.28 (0.04–0.54)	0.54 (0.36–0.84)	5.83 (4.64–7.01)	2.41 (1.89–2.99)	2.43 (2.01–2.84)	1.48 (1.29–1.67)

Legend:

Data sources

SAVVY: Analysis of Sample vital registration with verbal autopsy

GBD: Extracted from Global Burden of Disease report