Effects of provider incentives on dental X-raying in NHS Scotland: what happens if patients switch providers?

Background: In many market settings individuals are encouraged to switch health care providers as a means of ensuring more competition. Switching may have a potentially undesirable side effect of increasing unnecessary treatment. Focusing on the most common source of medical radiation (dental X-rays), the purpose of this study was to assess whether, upon switching dentist, X-ray exposure increases depending on the type of provider payment.
Methods: The analysis used longitudinal data from 2005 to 2016 covering a 5% random sample of the Scottish adult population covered by the National Health Service (NHS). Multiple fixed-effects panel regression analyses were employed to determine the correlation of provider remuneration with patients' likelihood of receiving an X-ray upon switching to a new dentist other things equal. A broad set of covariates including a patient's copayment status was controlled for.
Results: Upon switching to a dentist who was paid fee-for-service, patients had a by 9.6%-points (95% CI 7.4-11.8%) higher probability of receiving an X-ray, compared to switching to a salaried dentist. Results were robust when accounting for patient exemption status, as well as unobserved patient and dentist characteristics.
Conclusions: In comparison to staying with the same dentist, patients may be exposed to substantially more X-rays upon switching to a dentist who is paid fee-for-service. There may need to be better guidance and regulation to protect the health of those who have to switch provider due to moving and greater caution in advocating voluntary switching.
(© 2021. The Author(s).)