Little is known about medication adherence among Asians and Asian Americans in psychiatric treatment.

We conducted a systematic review of studies of Asian American and Asian patients with depression or schizophrenia to understand adherence rates and tools used to measure adherence.

A key word search of PubMED and PsycINFO, restricted to journal articles available in English or Chinese and published between 1960 and March 2010 was performed. Reference lists of studies meeting inclusion criteria were manually reviewed and content experts were consulted. Two investigators independently reviewed all identified publications for inclusion using predetermined criteria and a pilot tested data-abstraction form.

Of the 1520 journal articles retrieved, 10 met criteria for inclusion. Adherence rates among patients with schizophrenia ranged from 5–71%; adherence rates among patients with depression ranged from 16–67%. Adherence rates varied among Asian sub-populations: Chinese patients’ rates ranged from 6–56%; Taiwanese patients’ rate was 46–61%; Asian American patients’ rate was 16%; Japanese patients’ rate was 56–71%; and Singaporean patients’ rate was 4.3%. Adherence was measured by: self-report; blood levels; refill rates; chart review; or physician/nurse or family caregiver report.

Medication adherence rates varied across clinical populations and country of origin. Nearly all of the rates are lower than many clinicians would consider acceptable. A critical step to research on improving adherence will involve reaching consensus on how to measure rates.