Screening for serious mental illness in the general population with the K6 screening scale: results from the WHO World Mental Health (WMH) survey initiative

Data are reported on the background and performance of the K6 screening scale for serious mental illness (SMI) in the World Health Organization (WHO) World Mental Health (WMH) surveys. The K6 is a six-item scale developed to provide a brief valid screen for Diagnostic and Statistical Manual of Mental Disorders 4th edition (DSM-IV) SMI based on the criteria in the US ADAMHA Reorganization Act. Although methodological studies have documented good K6 validity in a number of countries, optimal scoring rules have never been proposed. Such rules are presented here based on analysis of K6 data in nationally or regionally representative WMH surveys in 14 countries (combined N = 41,770 respondents). Twelve-month prevalence of DSM-IV SMI was assessed with the fully-structured WHO Composite International Diagnostic Interview. Nested logistic regression analysis was used to generate estimates of the predicted probability of SMI for each respondent from K6 scores, taking into consideration the possibility of variable concordance as a function of respondent age, gender, education, and country. Concordance, assessed by calculating the area under the receiver operating characteristic curve, was generally substantial (median 0.83; range 0.76-0.89; inter-quartile range 0.81-0.85). Based on this result, optimal scaling rules are presented for use by investigators working with the K6 scale in the countries studied. Copyright (c) 2010 John Wiley & Sons, Ltd.

Bristol-Myers Squibb

Eli Lilly & Company Foundation

GlaxoSmithKline

Johnson & Johnson Pharmaceuticals

Ortho-McNeil Pharmaceuticals Inc.

Pfizer Inc.

Sanofi-Aventis

United States National Institute of Mental Health (NIMH/NIH)[R01MH070884]

John D. and Catherine T. MacArthur Foundation

Pfizer Foundation

US Public Health Service[R13-MH066849]

US Public Health Service[R01-MH069864]

US Public Health Service[R01 DA016558]

Fogarty International Center (FIRCA/NIH)[R03-TW006481]

Pan American Health Organization (PAHO)

Shire

State of Sao Paulo Research Foundation (FAPESP)[03/00204-3]

Ministry of Health and the National Center for Public Health Protection

Shenzhen Bureau of Health

Shenzhen Bureau of Science, Technology, and Information

Ministry of Social Protection

WHO (India)

Japan Ministry of Health, Labour, and Welfare[H13-SHOGAI-023]

Japan Ministry of Health, Labour, and Welfare[H14-TOKUBETSU-026]

Japan Ministry of Health, Labour, and Welfare[H16-KOKORO-013]

Lebanese Ministry of Public Health

WHO (Lebanon), Fogarty International (FIRCA/NIH), Act for Lebanon

Janssen Cilag

Roche

Novartis

The National Institute of Psychiatry Ramon de la Fuente (INPRFMDIES)[4280]

National Council on Science and Technology[CONACyT-G30544-H]

Pan American Health Organization (PAHO)

New Zealand Ministry of Health, Alcohol Advisory Council

Health Research Council

WHO (Geneva)

WHO (Nigeria)

Federal Ministry of Health, Abuja, Nigeria

Ministry of Public Health

Eli Lilly Romania SRL

US National Institute of Mental Health (NIMH/NIH)[R01-MH059575]

US National Institute of Mental Health (NIMH/NIH)[RO1-MH61905]

US National Institute of Mental Health (NIMH/NIH)[U01-MH60220]

South African Department of Health

University of Michigan

National Institute of Drug Abuse (NIDA/NIH)

Substance Abuse and Mental Health Services Administration (SAMHSA)

Robert Wood Johnson Foundation (RWJF)[044708]

John W. Alden Trust