How operational research-driven differentiated TB care initiative helped reduce TB deaths in Tamil Nadu
Tamil Nadu’s differentiated TB care initiative — Tamil Nadu Kasanoi Erappila Thittam (TN-KET) or TB death-free initiative — was launched for the first time in India in April 2022 to reduce TB deaths. In just six months after its launch, early deaths reduced by 20% and overall deaths reduced by 10% at the State level; in 2024, over two-thirds of the districts documented at least 20-30% reduction in TB death rate. The reason: the novel initiative is driven by operational research
Most public health initiatives carried out in India, newly launched ones included, adopt the conventional approach of waiting till the end of the programme to understand the deficiencies and limitations. In contrast, incorporating operational research to the existing monitoring and evaluation immensely helps in tracking the programme and making changes on the go.
Tamil Nadu’s differentiated TB care initiative — Tamil Nadu Kasanoi Erappila Thittam (TN-KET) or TB death-free initiative — launched for the first time in India in April 2022 across Tamil Nadu is a State-specific initiative with a stated objective of reducing TB deaths. Under the differentiated TB care strategy, all adults with TB are triaged for severe illness at the time of diagnosis, and triage-positives (severely ill) are prioritised for referral, comprehensive clinical assessment, and inpatient care. The triaging happens in all the public health facilities in Tamil Nadu that diagnose TB.
Triaging for severe illness at the time of diagnosis is to cut the delay in providing critical care soon after diagnosis to prevent early deaths — deaths that take place in the first two months after diagnosis, which is almost 70% of all TB deaths among notified TB patients. In just about six months after TN-KET was launched in all districts except Chennai, early deaths reduced by 20% and overall deaths reduced by 10% at the State level. Average time to death after diagnosis doubled from less than 20 days before April 2022 to 40 days in July 2022. Based on data up to September 2023, some districts in Tamil Nadu started showing consistent reduction in TB deaths — death rate reduced from 12.5% to 7.8% in Dharmapuri, 7.1% to 5.3% in Karur, and 6.1% to 5.2% in Villupuram. In 2024, more than two-thirds of the districts in Tamil Nadu documented at least 20-30% reduction in TB death rate.
One of the reasons for the significant achievement of the initiative in reducing TB deaths within a short time is because TN-KET is driven by operational research.
What is operational research?
Operational research in health is defined as any research that produces practical usable knowledge to improve health programme implementation irrespective of the type of research. Some experts use the term implementation research. Irrespective of the terminology used, one thing is clear: operational research helps in improving real world implementation of health programmes. The research questions could be themed around generating knowledge around constraints, testing new tools or initiatives or existing ‘inefficient’ tools or initiatives in how they need to be modified. The key here is that any new tool or initiative or modification of existing tool or initiative should be implemented and monitored by the existing health workforce in routine health system settings. The co-design may be jointly done by experts in operational research and those involved in programme management and implementation.
Any health programme involves planning, implementation, monitoring and evaluation. Implementation involves who will do what, when and how and how it will be recorded and reported. Indicators are generated usually involving aggregate numbers generated from existing recording/reporting mechanisms.
How is operational research different from routine monitoring and evaluation? First, to begin with there is a synergy between routine monitoring and data used in operational research. Most operational research questions can be answered using existing data collected by the health programme called secondary data. Second, operational research, like any other research, is more rigorous and systematic than routine monitoring and evaluation.
How operational research guides TN-KET
We at ICMR National Institute of Epidemiology (ICMR-NIE) provide lead technical support in the ongoing initiative to triage for severe illness at the time of diagnosis followed by appropriate inpatient care. TN-KET uses a one-page paper-based triage tool that relies on just three conditions — very severe undernutrition, respiratory insufficiency, and inability to stand without support — to prioritise patients for referral, comprehensive clinical assessment and admission at the nodal inpatient care facilities in the district. These conditions are identified by measuring five variables — body mass index, pedal oedema, respiratory rate, oxygen saturation and ability to stand without support.
Key variables from the paper-based tirage tool and case record form (for severely ill) are transcribed into Severe TB Web Application (TB SeWA), the initiative’s TB information management system to identify and track severely ill adults with TB. TNKET has been successful in documenting implementation fidelity and reduction in TB death rate in the State.
From the operational research point of view, we answered the prior agreed research questions that cannot be answered by routine monitoring and evaluation alone. Operational research in June-July 2022 from eight medical colleges of the State, provided evidence in favour of triaging using five variables in TN-KET instead of the nationally recommended assessment using 16 indicators. Using the data available in TB SeWA and Ni-kshay (TB programme’s case-based information management system), we were able to analyse and identify predictors of not getting triaged, not getting admitted and poor admission outcomes. Through individual level data analysis, we identified the time interval in the care cascade. Operational research on quality of triaging and comprehensive assessment has guided ongoing implementation. Routine monitoring and evaluation based on aggregate numbers has provided evidence in favour of reduction in TB death rates across quarters following differentiated TB care implementation. But it was operational research (through confounder adjusted analysis) that helped us document that this was attributed to the novel initiative and not due to differences in characteristics of people diagnosed with TB across quarters.
Beginning October 2024, TN-KET added the component of identifying and managing uncontrolled glycemic status during TB treatment among people with TB and Diabetes. A TB-DM module has been added to TB SeWA. From July 2025, based on the triage variables entered at TB diagnosis, TB SeWA not only provides information on whether the adult with TB is severely ill but also provides the predicted probability of TB death for the individual which is as high as 10-50% for severely ill compared with 1-4% for someone who is not severely ill. This helps in overcoming any subjective inference of severity by the staff involved in triaging and will contribute towards immediate admission of the severely ill.
There is no doubt from our side that the key role is played by the State TB Cell with support from District TB Cells, WHO medical consultant network, Directorate of Medical Education, Directorate of Medical and Rural Health Services, Directorate of Public Health and Preventive Medicine and Tamil Nadu National Health Mission. At the same time, ICMR-NIE also plays its part by providing lead technical support in planning, implementation, monitoring, supportive supervision and operational research. In doing this, we followed certain guiding principles.
Guiding principles
ICMR-NIE followed four broad guiding principles that have contributed towards TN-KET’s success. First, we provided a commitment of long-term technical support. Many externally supported operational research projects do not see the light at the end of the tunnel or the initiative is not sustained after external support stops or after the project gets over. What the States also require is technical support in routine implementation and monitoring. Hence, TN-KET was envisioned as an implementation project with a built-in operational research component. Some nodal persons in the ICMR-NIE TN-KET technical support unit are linked to district TB cells and some to the State TB cell. We developed TB SeWA, the State-specific TB information management system for severely ill adults with TB in the State.
Second, we were clear from day one that the initiative has to be implemented by the existing health workforce in routine health system settings and monitored by the district and State TB cell. The process indicators used for monitoring of TN-KET should be part of routine monthly/quarterly performance review of the TB programme in the State. Whenever, the national TB elimination programme is reviewed at district level by the State, TN-KET is also reviewed.
Third, we treat TN-KET as the State’s baby and not the ICMR-NIE’s. The day it is seen as the baby of ICMR-NIE, it will fail. This fosters a sense of commitment and ownership of the initiative within the State health system. We hardly break the line of command and always work with the State TB Officer who leads implementation of the initiative.
Finally, to minimise the digital data burden on staff, we ensure that there is no duplication of data that is captured in Ni-kshay and TB SeWA. Additionally, TB SeWA only captures key variables (from paper-based tools) that are required to generate the process indicators to monitor the initiative.
(For more details and tips, readers can read our research article (Practice Paper) published in Global Health Action. Those interested in a practitioner’s perspective on operational research, there is a Podcast on Spotify.)
Learnings for ICMR-NIE
Working alongside the State on this initiative has helped ICMR-NIE learn a few important lessons. First, operational research can be done by utilising existing resources without the need for project-specific funding. Most of the staff of the TN-KET technical support unit are permanent scientists and technical staff of the institute. Second, the importance of untied funds to support operational research. TN-KET is a non-funded initiative without any project-specific funding. We are utilising existing resources within the institute to provide the supportive supervisory visits and publication costs. Hence, if we have untied funds within an institute (like we generated for TN-KET), many such operational research projects can be simultaneously supported (leveraging the technical support unit). On the lines of TN-KET, we are now considering other State-specific operational research projects. Institutes that intend to excel in operational research should consider generating untied funds that can be used across projects.
Finally, outputs of the research project are not the end-result. Ongoing research publications from an operational research project can act as a medium of policy/practice change. While TN-KET began in April 2022 as an implementation project with a built-in operational research component, the initial publications in 2023-2024 were on how we implemented the initiative with focus on feasibility. From 2025 onwards, we are in the process of publishing articles on the impact on TB death reduction. All these publications are jointly led by the State TB cell and ICMR-NIE.
Time to prioritise operational research
To summarise, unlike the conventional approach of waiting till the end of the programme to understand the deficiencies, the use of operational research supports the ongoing monitoring and evaluation in the programme and immensely helps in tracking and making changes on the go. Despite the clear advantages of using operational research in public health initiatives, this has not been adopted in most cases. And if adopted, it is mostly outsourced to external agencies. Health programmes and initiatives should identify priority operational research questions and answer them. To do this, either they should build their capacity in operational research or work in collaboration with experts in operational research.
