Cost-Effectiveness Analysis of Community Active Case Finding and Household Contact Investigation for Tuberculosis Case Detection in Urban Africa

<div><p>Introduction</p><p>Case detection by passive case finding (PCF) strategy alone is inadequate for detecting all tuberculosis (TB) cases in high burden settings especially Sub-Saharan Africa. Alternative case detection strategies such as community Active Case Finding (ACF) and Household Contact Investigations (HCI) are effective but empirical evidence of their cost-effectiveness is sparse. The objective of this study was to determine whether adding ACF or HCI compared with standard PCF alone represent cost-effective alternative TB case detection strategies in urban Africa.</p><p>Methods</p><p>A static decision modeling framework was used to examine the costs and effectiveness of three TB case detection strategies: PCF alone, PCF+ACF, and PCF+HCI. Probability and cost estimates were obtained from National TB program data, primary studies conducted in Uganda, published literature and expert opinions. The analysis was performed from the societal and provider perspectives over a 1.5 year time-frame. The main effectiveness measure was the number of true TB cases detected and the outcome was incremental cost-effectiveness ratios (ICERs) expressed as cost in 2013 US$per additional true TB case detected.</p><p>Results</p><p>Compared to PCF alone, the PCF+HCI strategy was cost-effective at US$443.62 per additional TB case detected. However, PCF+ACF was not cost-effective at US$1492.95 per additional TB case detected. Sensitivity analyses showed that PCF+ACF would be cost-effective if the prevalence of chronic cough in the population screened by ACF increased 10-fold from 4% to 40% and if the program costs for ACF were reduced by 50%.</p><p>Conclusions</p><p>Under our baseline assumptions, the addition of HCI to an existing PCF program presented a more cost-effective strategy than the addition of ACF in the context of an African city. Therefore, implementation of household contact investigations as a part of the recommended TB control strategy should be prioritized.</p></div

One-way Sensitivity Analysis for Cost-effectiveness of TB Case Finding Strategies Varying Probabilities and Costs.

<p>^aICER = Incremental Cost- Effectiveness Ratio</p><p>^b Ranges obtained from published literature, expert opinion, or full ranges used</p><p>^<b>c</b> PCF+ACF becomes cost-effective at high probability of chronic cough, ICER below decision threshold of US$ 1,102.00</p><p>^d PCF+HCI is no longer cost effective at low probability of case detection, ICER above decision threshold</p><p>^<b>e</b> PCF+ACF becomes a cost-effective at low ACF program cost, ICER below decision threshold</p><p>One-way Sensitivity Analysis for Cost-effectiveness of TB Case Finding Strategies Varying Probabilities and Costs.</p

Summary of Cost (in 2013US$) Estimates Associated with TB Detection.

<p>a: Program costs include administration, transport, communication & health personnel</p><p>b: Direct medical costs include Smear tests, culture tests, CXR & consumable supplies</p><p>c: Total patient and care giver costs include direct (transportation& meals) and, Indirect costs (productivity/wages lost)</p><p>d: Estimated total per patient costs are a summation of program, direct medical and total patient-caregiver costs estimated in each strategy</p><p>Summary of Cost (in 2013US$) Estimates Associated with TB Detection.</p

Decision Tree for the Passive Case Finding <i>plus</i> Active Case Finding Strategy.

<p>Decision Tree for the Passive Case Finding <i>plus</i> Active Case Finding Strategy.</p

Decision Tree for the Passive Case Finding Strategy.

<p>Decision Tree for the Passive Case Finding Strategy.</p

Incremental Cost-effectiveness Ratios from the Societal Perspective Referencing PCF as a Common Baseline.

<p>a: Effectiveness are rounded to the nearest whole number per 1000 person screened in the target population</p><p>b: ICER- Incremental Cost-Effectiveness Ratio (incremental cost divided by incremental effectiveness)</p><p>*calculations of ICERs do not exactly match direct division of incremental cost and incremental effectiveness as shown in table because we used up to 5 significant digits for effectiveness numbers to increase precision and minimize rounding errors</p><p>Incremental Cost-effectiveness Ratios from the Societal Perspective Referencing PCF as a Common Baseline.</p

Incremental Cost-effectiveness Ratios from the Provider Perspective Referencing PCF as a Common Baseline.

<p>a: Effectiveness are rounded to the nearest whole number per 1000 person screened in the target population</p><p>b:ICER- Incremental Cost-effectiveness Ratio (incremental cost divided by incremental effectiveness)</p><p>*calculation of ICERs do not exactly match direct division of incremental cost and incremental effectiveness as shown in table because we used up to 5 significant digits for effectiveness numbers to increase precision and minimize rounding errors</p><p>Incremental Cost-effectiveness Ratios from the Provider Perspective Referencing PCF as a Common Baseline.</p

Probabilities Estimates Used in Decision Analytic Model.

<p>Probabilities Estimates Used in Decision Analytic Model.</p