Thomas E. Matson, PhD, MPH

Credit: Kaiser Permanente Washington Health Research Institute

A new symptom checklist could help enable primary care physicians to better diagnose and assess the severity of patients with substance use disorder (SUD).¹

A team, led by Thomas E. Matson, PhD, MPH, Kaiser Permanente Washington Health Research Institute, evaluated the psychometric properties of the Substance Use Symptom Checklist used in primary care among patients who report daily cannabis use and/or other drug use.

Substance Use Disorder

SUDs are commonly underrecognized in primary care settings, largely because structured clinical interviews can be infeasible. However, 1 potential option is a brief, standardized substance use symptom checklist to help assess SUD.

In the cross-sectional study, the investigators examined adult primary care patients who completed the symptom checklist during routine care at an integrated health care system between March 1, 2015 and March 1, 2020.

The new checklist involved 11 items corresponding to SUD criteria in the Diagnostic and Statistical Manual for Mental Disorders (Fifth Edition) (DSM-5).

The team used item response theory analyses to decipher whether the symptom checklist was unidimensional and reflected a continuum of SUD severity. They also evaluated item characteristics in discrimination and severity.

Finally, they used a differential item functioning analyses to identify whether the symptom checklist performed similarly across age, sex, race, and ethnicity and the analyses was stratified by cannabis and/or other drug use.

The Patients

The study involved 23,304 individuals screened with a mean age of 38.2 years. Of this group, 16,140 patients reported daily cannabis use only, 4791 patients reported other drug use only, and 2373 patients reported both daily cannabis and other drug use.

The results show 26.3% (n = 4242) of patients in the daily cannabis use only group endorsed 2 or more items on the symptom checklist, consistent with DSM-5 SUD, compared to 30.2% (n = 1446) of the other drug use group and 51.8% (n = 1229) of the daily cannabis and other drug use group.

The IRT models support the unidimensionality of the symptom checklist and all items discriminated between higher and lower levels of SUD severity in all cannabis and drug subsamples.

The investigators observed differential item functioning for some items across sociodemographic subgroups. However, this did not result in any meaningful changes in the overall score.

“In this cross-sectional study, a symptom checklist, administered to primary care patients who reported daily cannabis and/or other drug use during routine screening, discriminated SUD severity as expected and performed well across subgroups,” the authors wrote. “Findings support the clinical utility of the symptom checklist for standardized and more complete SUD symptom assessment to help clinicians make diagnostic and treatment decisions in primary care.”

References:

Matson TE, Hallgren KA, Lapham GT, et al. Psychometric Performance of a Substance Use Symptom Checklist to Help Clinicians Assess Substance Use Disorder in Primary Care. JAMA Netw Open. 2023;6(5):e2316283. doi:10.1001/jamanetworkopen.2023.16283