PHQ-2 screening followed by PHQ-9 may provide accurate depression detection
Administration of the Patient Health Questionnaire-2, or PHQ-2, followed by the PHQ-9 appeared to be an effective method for accurate depression screening, according to results of a systematic review and meta-analysis published in JAMA.
“Although depression screening is often recommended, evidence on screening accuracy is largely based on small studies that may be biased in important ways,” Brooke Levis, PhD, of the Lady Davis Institute for Medical Research at Jewish General Hospital, told Healio Psychiatry. “We wanted to obtain and combine data from as many studies as possible to get very precise estimates of the accuracy of a common depression screening method.”
Because depression screening can be resource intensive, Levis and colleagues sought to determine whether the fewer-item PHQ-2 could be used to identify at-risk individuals who then could be evaluated with the PHQ-9. They searched four databases and included studies with data sets that compared PHQ-2 scores with major depression diagnoses from a validated diagnostic interview. They synthesized individual participant data with bivariate random-effects meta-analysis using semi-structured, fully structured or Mini International Neuropsychiatric Interview (MINI) diagnostic interviews. Scores range from zero to 27 on the PHQ-9 and from zero to six on the PHQ-2.
Data from 100 studies revealed PHQ-2 sensitivity and specificity were 0.91 and 0.67 for cutoff scores of two or greater, and 0.72 and 0.85 for cutoff scores of three or greater among studies that used semi-structured interviews. Levis and colleagues noted significantly greater sensitivity for semi-structured vs. fully structured interviews; however, specificity was similar across interview types. The area under the receiver operating characteristic curve was 0.88 for semi-structured interviews, 0.87 for the MINI and 0.82 for fully structured interviews.
The researchers observed no significant subgroup differences.
Sensitivity for PHQ-2 scores of two or greater followed by PHQ-9 scores of 10 or greater was not significantly different than PHQ-9 scores of 10 or greater alone for semi-structured interviews; however, specificity was significantly but minimally higher for the combination. Levis and colleagues estimated the combination reduced the number of participants needing to complete the full PHQ-9 by 57%.
“If depression screening is done in clinical care or in research, using the brief PHQ-2 in combination with the PHQ-9 is much more efficient than using the full PHQ-9 for everybody, and it is just as accurate,” Levis told Healio Psychiatry. “Although clinical trials have not yet found that depression screening improves mental health, this method can be used in new trials that test whether this can be achieved.”