A genetic test can promise safer, more effective prescribing—but this study found that whether clinicians use it may depend just as much on how the service is built as on the test itself. Primary care is handling more prescriptions while contacts are becoming more numerous and complex.

The NHS Long Term Plan recognised this pressure and called for more informed prescribing. That plan also aimed to support informed prescribing by reducing ineffective treatment, avoiding overprescribing, and preventing problematic combinations of medicines.

Pharmacogenetic testing in the NHS has historically been reactive, used for single gene-drug relationships in specialist settings. This study asks what a testing service would need to look like in primary care. Clinicians were shown different service options and asked which they preferred, including no test.

Everyone preferred pharmacogenetic testing over no testing, although preferences differed. The choice question asked which of two tests would help guide a patient’s treatment. The survey also included an option representing no pharmacogenetic test, reflecting current prescribing.

That made it possible to examine not just which version clinicians liked better, but whether they would choose testing at all. Both professional groups preferred receiving a narrow set of pharmacogenetic information rather than other reporting strategies. Focused reporting was linked with lower uptake in both groups.

A broad report increased uptake for pharmacists, but reduced uptake for general practitioners. More information was therefore not automatically more appealing. Changes to the basic service meaningfully affected predicted uptake for both professional groups, and general practitioners were the most sensitive to those changes.

With the same small improvement in medicine effectiveness, the basic service produced much lower predicted uptake than the optimised service for both groups. Changing the service design could improve predicted uptake by up to 41.1% for pharmacists and up to 59.9% for general practitioners.

The findings show that respondents preferred pharmacogenetic testing over no testing. But both groups, especially general practitioners, were highly sensitive to service design. Preferences did not differ by whether the clinical situation involved low mood or joint pain, but they did differ by professional role.

Pharmacogenetic testing was highly acceptable in primary care, but only if the service was designed appropriately. Making testing available is not enough; the full clinical pathway also needs connected digital and data systems. That will require dedicated resources, expertise, and clinical stakeholders involved from the outset.

The organisational and financial challenges will be substantial, but the potential rewards could also be considerable. Clinicians preferred testing, but they did not want just any testing service. Clear, focused information and a well-connected clinical system could determine whether this idea reaches patients in everyday care.