Adaptation of WHO’s generic tuberculosis patient cost instrument for a longitudinal study in Africa

ABSTRACT

The WHO developed a generic ‘TB patient cost survey’ tool and a standardized approach to assess the direct and indirect costs of TB incurred by patients and their households, estimate the proportion of patients experiencing catastrophic costs, and measure the impact of interventions to reduce patient costs. While the generic tool is a facility-based cross-sectional survey, this standardized approach needs to be adapted for longitudinal studies. A longitudinal approach may overcome some of the limitations of a cross-sectional design and estimate the economic burden of TB more precisely. We describe the process of creating a longitudinal instrument and its application to the TB Sequel study, an ongoing multi-country, multi-center observational cohort study. We adapted the cross-sectional WHO generic TB patient cost survey instrument for the longitudinal study design of TB Sequel and the local context in each study country (South Africa, Mozambique, Tanzania, and The Gambia). The generic instrument was adapted for use at enrollment (start of TB treatment; Day 0) and at 2, 6, 12 and 24 months after enrollment, time points intended to capture costs incurred for diagnosis, during treatment, at the end of treatment, and during long-term follow-up once treatment has been completed. These time points make the adapted version suitable for use in patients with either drug-sensitive or drug-resistant TB. Using the adapted tool provides the opportunity to repeat measures and make comparisons over time, describe changes that extend beyond treatment completion, and link cost survey data to treatment outcomes and post-TB sequelae.

Trial registration: ClinicalTrials.gov: NCT032516 August 1196, 2017.

Abbreviations: DOTS: Directly observed treatment, short-course; DR-TB: Drug-resistant tuberculosis; MDR-TB: Multi-drug resistant tuberculosis; NTP: National Tuberculosis Programme; TB: Tuberculosis; USD: United States Dollar; WHO: World Health Organization.

KEYWORDS:

• Catastrophic total costs
• income
• pre-treatment
• out-of-pocket
• TB sequelae

Responsible Editor

Jennifer Stewart Williams, Umeå University, Sweden

Responsible Editor

Jennifer Stewart Williams, Umeå University, Sweden

Acknowledgments

We would like to recognize the hard work and valuable contributions of all colleagues and partners in this project. We are also thankful to representatives of NTPs and representatives of other national health authorities for their support from early stages of the project.

Author contributions

AR, IS, SR, KL conceptualized and designed the work. DE, KL, AS and OI developed the different versions of the instrument. AS and KL provided input regarding analytical considerations. CvR and CG provided training and together with CG, AKS, IJ, NN and IS input for local adaptation and refinement. FB provided input into data collection and management. DE wrote the manuscript. All authors critically reviewed and approved the final version of the manuscript.

Disclosure statement

Authors do not have any competing interests to declare.

Ethics and consent

This study has been reviewed and approved by all respective Ethics Committees at each study site and also for coordinating institutions [2]. All participants enrolled in the TB Sequel study provide written informed consent before enrollment in the study. Participants are assigned a unique study identification number for identification purposes, and all electronic data extracted from the clinical data management system is de-identified.

Paper context

The WHO cross-sectional TB patient cost tool was developed to enable countries to monitor the End TB indicator, namely, to eliminate the number of TB-affected households facing catastrophic costs by 2035. We adapted the generic tool, typically designed for national surveillance studies, for longitudinal studies. The adapted tool can now be used to make comparisons over time, describe changes that extend beyond treatment completion, and link cost survey data to treatment outcomes and post-TB sequelae.

ORCID details

Van Rensburg ([email protected]; ORCID identifier 0000-0003-0458-3306),

Govathson ([email protected]; ORCID identifier 0000-0003-2595-1913),

Ivanova ([email protected]; ORCID identifier 0000-0002-8276-7891),

Rieß ([email protected]),

Siroka ([email protected]; ORCID identifier 0000-0002-0320-0775),

Sillah K ([email protected]; ORCID identifier 0000-0001-8332-2475),

Ntinginya ([email protected]; ORCID identifier 0000-0002-1575-4521),

Jani ([email protected]; ORCID identifier 0000-0002-6880-6655),

Sathar ([email protected]; ORCID identifier 0000-0002-8296-8554),

Rosen ([email protected]; ORCID identifier 0000-0002-6560-2964),

Sanne ([email protected]; ORCID identifier 0000-0003-4729-3405),

Rachow ([email protected]; ORCID identifier 0000-0002-4269-3699),

Lönnroth ([email protected]; ORCID identifier 0000-0001-5054-8240).

TB Sequel Consortium members

Gavin Churchyard, Michael Hoelscher, Robert Wallis, Salome Charalambous, Kavindhran Velen, Farzana Sathar, Fadzai Munedzimwe, Andrea Rachow, Olena Ivanova, Anna-Maria Mekota, Abhishek Bakuli, Christof Geldmacher, Friedrich Riess, Fidelina Zekoll, Ulrich von Both, Knut Lönnroth, Stefan Nimann, Matthias Merker, Viola Dreyer, Ulrich Schaible, Christoph Leschczyk, Beate Kampmann, Jayne Sutherland, Basil Sambou, Caleb Muefong, Fatoumatta Darboe, Abi-Janet Riley, Binta Sarr, Olumuyiwa Owolabi, Ben Dowsing, Azeezat Sallahdeen, Shamanthi Jayasooriya, Abdou K Sillah, Nyanda Elias Ntinginya, Issa Sabi, Daniel Mapamba, Mkunde Chachage, Elimina Siyame, Julieth M. Lalashowi, Ian Sanne, Mohammed Rassool, Lyndel Singh, Jaclyn Bennet, Noluthando Mwelase, Ilesh Jani, Celso Khosa, Nilesh Bhatt, Sofia Viegas, Khalide Azam, Nadia Sitoe, Pedroso Nhassengo, Denise Evans, Kamban Hirasen, Caroline Govathson, Tembeka Sineke, Sydney Rosen.

Additional information

Funding

This project was funded by the German Ministry for Education and Research (BMBF) and is a part of the Research Networks for Health Innovations in Sub-Saharan Africa.