Publications

Tuberculosis (TB) remains an important problem among end-stage renal disease (ESRD) patients. We reviewed the epidemiology of TB and ESRD, investigations of TB exposures in US dialysis facilities, and published guidelines to inform screening and treatment practices among US ESRD patients. Compared to TB in the general population, ESRD patients have 6-25-fold higher TB incidence rates, and mortality during treatment is 2-3-fold higher. Most TB cases among ESRD patients (~90%) occur among non-US-born persons, and an analysis of genotyping data suggests that 80% of all cases result from latent TB infection (LTBI) reactivation. Published TB contact investigations in dialysis facilities have reported cases among ESRD patients and healthcare workers. However, transmission of TB is rare: there were no reports of secondary cases of TB because of exposure to an index-case patient and there were few TB infections, which was demonstrated by low occurrence of newly positive tuberculin skin tests (12%-16%) and conversions (8%-17%) among contacts. Targeted TB education, screening, and treatment for ESRD patients at highest risk for TB exposure (eg, non-US-born persons), using interferon-gamma release assays and short course LTBI regimens (ie, isoniazid-rifapentine weekly for 12 weeks or rifampin daily for 4 months) may be an effective overall strategy for reducing TB burden in ESRD patients.

BACKGROUND

The objective of this study was to develop and validate a short form of the Patient Health Questionnaire-9 (PHQ-9), a self-report questionnaire for assessing depressive symptomatology, using objective criteria.

METHODS

Responses on the PHQ-9 were obtained from 7,850 English-speaking participants enrolled in 20 primary diagnostic test accuracy studies. PHQ unidimensionality was verified using confirmatory factor analysis, and an item response theory model was fit. Optimal test assembly (OTA) methods identified a maximally precise short form for each possible length between one and eight items, including and excluding the ninth item. The final short form was selected based on prespecified validity, reliability, and diagnostic accuracy criteria.

RESULTS

A four-item short form of the PHQ (PHQ-Dep-4) was selected. The PHQ-Dep-4 had a Cronbach's alpha of 0.805. Sensitivity and specificity of the PHQ-Dep-4 were 0.788 and 0.837, respectively, and were statistically equivalent to the PHQ-9 (sensitivity = 0.761, specificity = 0.866). The correlation of total scores with the full PHQ-9 was high (r = 0.919).

CONCLUSION

The PHQ-Dep-4 is a valid short form with minimal loss of information of scores when compared to the full-length PHQ-9. Although OTA methods have been used to shorten patient-reported outcome measures based on objective, prespecified criteria, further studies are required to validate this general procedure for broader use in health research. Furthermore, due to unexamined heterogeneity, there is a need to replicate the results of this study in different patient populations.