Study setting
Under Brazilian guidelines LTBI care is provided to child and adult HHC who have a positive tuberculin skin test (TST) or positive Interferon-Gamma Release Assay (IGRA). All treatment for LTBI is self-administered and LTBI is not a compulsory notifiable condition. (11)
This study was carried out in two clinics where the intervention trial had previously been implemented.
Study periods
The intervention trial was conducted from May to October of 2018. The follow-up study consisted of two components. Firstly, we conducted a retrospective analysis of the cascade of LTBI care of HHC of TB index-patients diagnosed between November 1, 2018 to March 31, 2019. Secondly, questionnaires were administered to TB index-patients, HHCs and HCWs between May 7, 2019 to July 4, 2019.
Intervention trial
The intervention trial consisted of a rapid public health evaluation to identify barriers to LTBI treatment for HHC of TB index-patients, followed by site specific selection of strengthening activities and implementation of interventions to the barriers. (10)
In Rio de Janeiro, Brazil, LTBI program strengthening interventions consisted of: (i) initial training covering all steps of the cascade of care in LTBI, (ii) intensified in-service training provided by a TB physician (weekly visits for the first two months, then every two weeks for two months, then once a month), (iii) development and use of a contact registry to facilitate a cascade analysis to support the in-service training of HCW, (iv) leaflets with educational information for TB index-patients and their contacts and (v) educational material developed for health care workers (TB booklet). (10)
After October 2018, all trial interventions were stopped. This meant cessation of in-service training, provision of leaflets to HHC and index patients, provision of the TB booklet to HCW, and no further on-site visits by research staff.
Follow-up study
For the cascade of LTBI care, we abstracted information from the TB registry at each clinic regarding the number of people recorded at each of the following steps: TB index-patient diagnosis, HHC identification, medical evaluation (including TST), and HHC initiating treatment. Only HHC of new microbiologically confirmed pulmonary TB patients (using acid fast bacilli (AFB) smear, TB culture, or Xpert®MTB/Rif) diagnosed between November 1, 2018 and March 31, 2019 were included in this cascade analysis. We excluded HHC with a diagnosis of active TB.
In the follow-up study, interviewer-administered open-ended structured questions were applied to TB index-patients, HHC and HCW. TB index-patients were eligible to be interviewed if they had confirmed (as defined above), or clinical pulmonary TB. HHC was defined as someone who slept in the same house at least one night per week, or spent more than one hour in the house at least five days per week, on average, with a TB index-patient, over the preceding three months. HCW were defined as doctor, nurse, auxiliary nurse or community health agent that assisted TB patients in either of the two clinics.
For the questionnaires on barriers and facilitators, a consecutive sample of all TB index-patients and their HHC presenting to both clinics from May 7, 2019 date to July 4, 2019 were invited to participate. The health clinic directors identified HCW from the TB programs; all were approached and accepted to participate.
For the questionnaires, semi-structured knowledge, attitudes and practices questionnaires were adapted from those used in the ACT4 trial. For HHC and TB index-patients, questions focused on perspectives and perceptions about the identification of contacts and reasons why linkage to LTBI care was or was not achieved. For HCW open ended questions related to motivation for contact tracing and continuation of activities implemented in the intervention trial were used. All questionnaires were interviewer-administered in the participating health clinics. All interviewees were 18 years of age or older. Written informed consent was provided by all participants prior to data gathering.
Outcomes
The two primary outcomes were the number of HHC identified and the number of HHC initiating LTBI treatment within three months of diagnosis of the TB index-patient. Both outcomes from the follow-up study (November 2018 to March 2019), were compared to: (i) the pre-trial intervention period (July-December 2017) of the intervention trial, and (ii) during the intervention period of the trial (May-October 2018). Outcomes were presented per 100 TB index-patients.
Secondary outcomes included: current barriers and facilitators to LTBI linkage to care, and acceptance and initiation of treatment identified by TB index-patients, HHC and HCW; and identifying the acceptability of study interventions from a HCW perspective.
Analysis
A Poisson regression model with identity link, accounting for over dispersion when necessary, was used to compare cascade of care data between the three time periods.
For questionnaire responses, open-ended questions were transcribed from audiotapes and coded by two independent reviewers (MYL, MLB) into common themes. Disagreements were resolved by consensus. The results from these common themes are presented as frequencies and proportions. We compared the responses of HHC and TB index-patients from the intervention trial questionnaires to the follow up study questionnaires using the Mantel-Haenszel method for adjusted odds ratio and Wald method for the confidence intervals.
Data analysis was performed using the statistical package R version 3.5.1 and Microsoft Office Excel 2016.
Ethical approval
The study was approved in Rio de Janeiro by the Municipal Health Ministry (CAAE 38278214.3.1001.5279) and by the McGill University Health Centre ethical review board (15-291-MUHC).
Role of funding source
This study was funded by the Canadian Institute of Health Research, grant number FDN-143350. The funder had no role in study design, data collection, data analysis, data interpretation, or writing of the report. The corresponding author had full access to all the data in the study and had final responsibility for the decision to submit for publication.