When less is more: Can reduced health monitoring improve medication adherence?

As the prevalence of chronic diseases rises, improving self-management has become an important determinant of the productivity of healthcare delivery. Recently, Mexico's largest healthcare provider began issuing automatic-refill prescriptions to stable hypertensive patients, thus reducing the frequency of health monitoring from 30- to 90-day intervals. Exploiting this change, I find that less monitoring implies no drawbacks in health outcomes and actually improves self-management of disease by increasing medication adherence when baseline monitoring is relatively frequent. The number of days when patients are out of medication between fillings falls by 2.2 days-an improvement in adherence of 6.4%. Furthermore, patients appear to value being on a low-frequency regime as they improve adherence in order to remain on it, suggesting that lower monitoring could be used as a "reward" to promote medication adherence or, potentially, other health behaviors. Finally, I find evidence of positive spillovers on adherence, as clinic congestion falls.