6 min readAug 11, 2025 07:30 AM IST
First published on: Aug 11, 2025 at 07:30 AM IST
The accurate diagnosis of a health disorder should precede the selection and judicious administration of effective therapies. Such a diagnosis is usually based on well-recorded medical history, careful clinical examination, and a set of laboratory tests that confirm or alter the initial diagnosis. Such tests can often project the likely course of the disease. Lack of access to diagnostic tests can result in a delayed or incorrect identification of the disorder, leading to mistimed or misdirected therapeutic approaches.
Universal health coverage (UHC), to which India committed in the National Health Policy of 2017 and also as a signatory of the UN Sustainable Development Goals (SDGs), requires high levels of service coverage and financial protection. Outpatient care accounts for over 60 per cent of the out-of-pocket expenditure for patients and their families. This involves personal expenditure on drugs, diagnostics, and transport. Health insurance policies only cover expenses incurred during hospitalisation. Absence of reliable diagnostic facilities in close-to-home public healthcare facilities reduces levels of both service coverage and financial protection.
While India’s private sector provides a wide array of diagnostic services, they are not within the easy reach of the urban poor or vast segments of the rural population. Despite the private sector trying to reach the last mile through point-of-care diagnostic devices and mobile clinics, many parts of rural India are dependent on diagnostic services in the public healthcare system. As are the urban poor. The objectives of UHC are well served only if the diagnostic facilities are available close to home — at the Ayushman Aarogya Mandir (Health and Wellness Centre at the sub-centre level) and the Primary Health Centre.
While deciding on the nature and range of diagnostic services to be provided at each level of care, attention has to be paid to the changing list of priority health problems over time. As demographic, socio-economic, environmental and nutrition transitions are occurring across India, rising rates of non-communicable diseases (NCDs) demand greater attention, alongside the stubbornly persisting infectious diseases. Cardiovascular diseases and diabetes now join tuberculosis and malaria in qualifying for early and accurate diagnostic assessment.
There have been remarkable advances in the diagnostic armamentarium of modern medicine. Advances in molecular diagnostics and imaging have vastly increased diagnostic precision. Some of these can be applied even in primary care settings. Tele-diagnostics (like tele-radiology, tele-pathology and tele-dermatology) are bridging gaps between diagnostic capacity in primary care and expertise in institutions of advanced healthcare. Technical capacity has also been augmented, with semi-auto analysers supplied to primary health centres and imaging capabilities enhanced in district hospitals.
While employing diagnostic tests across a health system, cost-effectiveness has to be taken into account as well. If multiple tests are available, which of them will yield the maximum diagnostic benefit? How much incremental value in diagnostic accuracy and correct clinical decision making will the more technically advanced but more expensive test add to the less expensive and more easily performed test? Which of the many tests should be performed sequentially, and which must run simultaneously? Diagnostic algorithms provided by the government must provide evidence-based guidelines on such questions. The Indian Council of Medical Research (ICMR) should lead this effort.
The National List of Essential Diagnostics (NLED), revised recently by the ICMR, after the first iteration in 2019, takes into account epidemiological and technological transitions in the country. There is also an earnest effort to enhance the scope of diagnostic services at the frontlines of primary care. As the number of diabetes and pre-diabetes cases mount in millions across the country, the ICMR recommends that blood samples be collected at the PHC level for estimating HbA1C levels to provide a three-month profile of blood sugar. These samples will then be transported to higher-level centres for analysis.
Rapid diagnostic tests for sickle cell anaemia, thalassaemia, Hepatitis B, and syphilis will now be available at the sub-centre level. Collection of samples for dengue testing will also be done at the sub-centre level. As climate change is rapidly increasing the geographic and seasonal span of mosquito-borne diseases, this is an essential measure. Many blood chemistry tests (for blood glucose levels, liver enzymes, and plasma cholesterol estimation) can now be performed at the PHC level. Dental X-rays will become available at the CHC level, as oral health is belatedly recognised as a priority for the health service.
The recent list recommends collecting samples for molecular TB testing right from the sub-centre level. Sputum samples collected at sub-centres and primary health centres will be transported to a higher centre. At the community health centre, sub-district and district hospitals, the ICMR recommends performing these tests in-house. India’s high burden of TB cases is also clouded by high numbers of latent cases and late detection. Improved TB diagnostics will enable these challenges to be effectively addressed.
All this is possible due to the extensive deployment of cost-effective molecular diagnostics equipment. While the value of molecular testing for TB was recognised in the past decades, the Covid pandemic directed public spotlight onto that laboratory technique. These machines reached across all layers of the health system, as RT-PCR became part of the common jargon. Less sensitive techniques, like microscopic examination for TB bacilli, will yield place to molecular testing. Drug-resistant TB is also easier to monitor with the availability of these testing methods.
Beyond the supply of testing equipment to primary and secondary healthcare settings, there is a need to build technical capacity for performing tests and interpreting results. We need to train more laboratory technicians while enabling frontline health workers to perform point-of-care diagnostic testing. Interpretation of test results requires the care provider to understand probability estimates (sensitivity, specificity, predictive values and likelihood ratios) to identify false positives and false negatives. Perhaps, AI can help in bridging these capacity gaps.
The writer is Distinguished Professor of Public Health, Public Health Foundation of India
While India’s private sector provides a wide array of diagnostic services, they are not within the easy reach of the urban poor or vast segments of the rural population. 
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