Cost-effectiveness of CRAG-LFA screening for cryptococcal meningitis among people living with HIV in Uganda

BMC Infectious Diseases

Table 1 Key Parameter Estimates

Parameter name	Value	Range	Source
Epidemiology
Number of patients enrolling in HIV care in Uganda per year	245,600	150,000–350,000	[34]
Total number of patients enrolling in HIV care per year with CD4 < 100 (% of total)	61,400 (25%)	13,000 (5%) -105,000 (30%)	[34]
Average age of cohort	37	32–44	[41]
Life Expectancy in years^a (on ART)	19.1	17–23	[41]
CRAG-positive prevalence (at baseline)	8.80%	1–20%	[20, 29, 31, 32]
Percentage of CRAG+ patients with baseline CM disease	25%	0–50%	[33, 45]
Proportion developing CM among CRAG positive patients without treatment^b	34%	10–75%	[21, 23, 31, 29]
Relative reduction in CM development among CRAG positive patients on CPET^b,c	65%	10–90%	[51, 26, 29, 31]
Proportion developing CM among CRAG negative patients^b	0.8%	0–2%	[10, 21, 29]
Treatment
Survival of diagnosed CM with full CM treatment	70%	50–90%	[30]
Survival of CM without treatment	0%
Relapse rate for treated CM^d	12.50%	9–16%	[26, 43]
Disability Weights
CM disease	0.615	0.46–0.77	[52, 53]
HIV (on ART)	0.053	0.039–0.066	[52, 53]
CM treatment	0.05	0.0375–0.0625	[52, 53] (Assumption)
Costs
CRAG-LFA	$2.52	$1.50–$10.00	[38]
Lumbar Puncture	$8.08	$6.03–$10.42	[35, 38]
CM Diagnosis (lab and staff costs)	$7.07	$2.42–$12.79	[35–38]
Preemptive treatment: Fluconazole 800 mg daily for 2 weeks, then 400 mg daily for 8 weeks	$22.22	$17.00–$33.00	[24, 35]
CM Treatment: Amphotericin B 0.7 mg/kg/day for 2 weeks, then fluconazole 800 mg for 3 weeks and fluconazole 400 for 9 weeks	$343.28	$200–$600	[33–35]

Abbreviations: CRAG-LFA cryptococcal antigen lateral flow assay, CPET WHO Cryptococcal Pre-emptive therapy, CM cryptococcal meningitis, ART antiretroviral therapy
^aLife expectancy was estimated to be reduced by 25% in CRAG positive individuals, independent of development of CM, to account for higher observed mortality in this population in recent cohort studies [20]
^bCRAG-LFA testing was a component of only the CRAG-LFA screening intervention; However, risk of progression to CM for all model arms was stratified based on epidemiologic data on prevalence of baseline CRAG positivity
^cAbsolute and relative risk reduction were calculated based on available studies of fluconazole therapy in CRAG positive patients [26, 29, 31]. An estimated 15% of patients in all model arms were considered lost to follow up over the time horizon of the model, with higher rates of CM development and relapse. Sensitivity analysis was conducted around these parameters
^dAssuming a 75% case detection rate for symptomatic CM disease

ISSN: 1471-2334