Table 4.
If a new diagnostic is to succeed in the Indian private market, then the popularity of commercial serology tests in India suggests that it should have the following characteristics.
| Test characteristic | Rationale |
|---|---|
| Should be perceived by doctors as a more sensitive and sophisticated test than sputum smears | Doctors often fear under-diagnosis of TB. They do not want to miss a TB case for ethical as well as monetary reasons (the patient will be under their treatment for months). They fear that their reputation will suffer if they offer to patients sputum smears or refer them to an RNTCP centre |
| Should be a rapid test – either a point-of-care* test which can be done in the clinic or a laboratory test that can produce results within the same day | Given the doctor-centric nature of the private healthcare, doctors need to draw monetary benefit from the procedure. A rapid test result ensures that patients will stay with the doctors and will not drop-out. Tests such as cultures are very unpopular among doctors because of the lengthy time delays and because they rarely influence doctor’s clinical decisions |
| Should be done on blood or urine sample and a single test should be sufficient for diagnosis | Stigma related to TB makes sputum a less desired sample. Also, patients with suspected TB or chronic fevers often give blood samples for other lab tests (ESR, CBC) and this will make a test based on sputum disadvantaged as compared to a test which can be done on the same blood sample. Also, doctors might be afraid that patients will not show up for a second visit if more than one test is needed to make diagnosis |
| Should be suitable for the detection of extrapulmonary TB | Neither sputum smear nor X-ray is suitable for detection of extrapulmonary TB. There is a highly unmet need for a test for this type of TB (genito-urinary TB in particular because it is considered a major cause of infertility in India). |
| Labs should not need to make big investments in infrastructure/equipment | Labs might be reluctant to invest in equipment/facility if they are not certain of a good volume of samples. This applies also to reagent rental schemes which oblige labs to buy a certain amount of reagents in a given time |
| It should not be too cheap or too expensive, but be in the middle range of about rupees 500 (price to the patient) in the private sector | The current private health care system is to a large extent driven by referral fees which are about 20–50% of the price which patients pay for the test. Any diagnostic test to be successful in the current scenario must assure a referral fee to doctors in a range of 150–300 Rupees per patient. Patients’ affordability dictates that the test should not significantly exceed rupees 500 (approx. 10 US$) or so |
Most Indian doctors do not perform any testing themselves in the clinic and they prefer to send patients to the labs, either because they are too busy to be doing testing, or they are nervous about interpreting rapid tests themselves. Also, sending patients to labs is much easier because kickbacks are assured. If they do the POC test themselves, then they have to charge the patient their consultation fees PLUS the rapid test fees and that might be seen as a problem for patients (who will not mind paying the lab). So, contrary to what is often thought, a POC test in India might not actually get used at the point of care.