Household Tuberculosis Contact¶
Label |
Definition |
|---|---|
TB |
Tuberculosis |
LTBI |
Latent Tuberculosis Infection |
AcTB |
Active Tuberculosis |
HHC |
Household Tuberculosis Contact |
TPT |
Tuberculosis Preventive Therapy |
TMREL |
Theoretical Minimum Risk Exposure Level |
Risk Exposure Overview¶
HHC is defined as individuals who living in a household with AcTB case. The HHC exposure is a dichotomous variable, exposure to this risk factor is associated with increased risk of progression to LTBI. HHC is not a risk factor included in GBD; however, it is one of the factors that indicates the population eligible for TPT. TPT is recommended by World Health Organization (WHO) for HHC living in high-TB incidence countries. Contact Investigation
Risk |
Outcome |
|---|---|
Household tuberculosis contact |
Latent tuberculosis infection |
The TMREL was defined as no AcTB case in household.
Vivarium Modeling Strategy¶
HHC is a dichotomous exposure modelled in Vivarium with two risk categories: living in a household with AcTB cases (exposed), and living in a household without AcTB cases (unexposed).
Data sources¶
To estimate the exposure of HHC, we utilized household structure data from Demographic and Health Surveys (DHS) and Integrated Public Use Microdata Series (IPUMS), combining with prevalence of AcTB from GBD 2019 to calculate what fraction of people for a given location-/age-/sex- would be living in a household with case of AcTB.
Component |
Source |
Notes |
|---|---|---|
Prevalence of AcTB |
GBD 2019 |
Sum of prevalence over cause_id 934, 946, 947, 948, 949, 950 |
Household structure |
household microdata from DHS and IPUMS |
Methods¶
For a selected location, we first load the household microdata that contains age and sex information for each unique household id; then we incorporate GBD 2019 age-/sex-specific AcTB prevalence to calculate the probability of individual free to AcTB in each household, according to the formula:
\(Pr_{no\; AcTB\; in\; HH_i} = \prod_{j\in HH_i} 1 - Pr_{j\; has\; AcTB}\)
Where, \(Pr_{j\; has\; AcTB}\) is the probability of a person j in household i has AcTB.
Next, we calculate the mean probability of free to AcTB across all households within each GBD age and sex group, described as below:
\(Pr_{no\; AcTB\; (age,\; sex)} = \frac{{}\sum_{i\in age,\; sex} Pr_{no\; AcTB\; in\; HH_i}}{total\; number\; of\; HH\; (age,\; sex)}\)
Lastly, we restrict our HHC population to individuals who live in a household with AcTB but don’t have AcTB themselves, and the fraction of HHC for a given GBD age and sex group is calculated as:
\(F_{HHC(age,\; sex)} = 1 - \frac{Pr_{no\; AcTB\; (age,\; sex)}}{1 - Prev_{AcTB(age,\; sex)}}\)
Access the Python code solution hh_tb_model
Validation Criteria¶
External validation by comparing to alternative derivation using other data sources.
References¶
- GBD 2019 TB prevalence
Vos T, Lim SS, Abbafati C, et al. Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019. The Lancet 2020; 396: 1204-22.
- Household structure for 5 high TB incidence countries (Global Health Data Exchange)
Central Statistical Agency (Ethiopia), ICF International. Ethiopia Demographic and Health Survey 2016. Fairfax, United States: ICF International, 2017.
ICF International, International Institute for Population Sciences (India), Ministry of Health and Family Welfare (India). India Demographic and Health Survey 2015-2016. Fairfax, United States: ICF International, 2018.
ICF International, Philippines Statistics Authority. Philippines Demographic and Health Survey 2013. Fairfax, United States: ICF International, 2014.
Minnesota Population Center, Statistics South Africa. South Africa Population and Housing Census 2011 from the Integrated Public Use Microdata Series, International: [Machine-readable database]. Minneapolis: University of Minnesota, 2015.
Macro International, Inc., National Institute of Statistics and Informatics (Peru). Peru Continuous Demographic and Health Survey 2012. Fairfax, United States: ICF International.