Table 2

Statistical appraisal of single- and two-question studies

Author	Phrase of questions	Criterion standard	Total sample	All cases	Non-cases	Unadjusted sensitivity	Unadjusted specificity	Unadjusted PPV	Unadjusted NPV
Single-question studies

Seale et al, 2006⁵¹	SASQ (When was the last time you had more than X drinks in one day?	Alcohol-use disorder (DSM-IV)	625	127	498	0.866	0.490	0.302	0.935

Fleming et al, 1991⁴⁷	Unique — Have you ever had a drinking problem?	Alcohol-use disorder (DSM-III)	280	82	198	0.573	0.879	0.662	0.833

	Unique — Do you have a current drinking problem?	Alcohol-use disorder (DSM-III)	280	82	198	0.317	0.970	0.813	0.774

Brown et al, 2001⁵⁰	Unique — In the last year, how many times have you not remembered things that happened while you were drinking or using drugs?	Substance Use Disorder (CIDI-SAM for DSM-III-R)	1136	261	875	0.483	0.925	0.656	0.857

	Unique — In the last year, have you ever drunk or used drugs more than you meant to?	Substance Use Disorder (CIDI-SAM for DSM-III-R)	1136	261	875	0.701	0.809	0.523	0.901

	Unique — Have you felt you wanted or needed to cut down on your drinking or drug use in the last year?	Substance Use Disorder (CIDI-SAM for DSM-III-R)	1136	261	875	0.563	0.917	0.668	0.876

	Unique — In the last year, have you drunk or used non-prescription drugs to deal with your feelings, stress, or frustration?	Substance Use Disorder (CIDI-SAM for DSM-III-R)	1136	261	875	0.544	0.869	0.553	0.865

	Unique — As a result of your drinking or drug use, did anything happen in the last year that you wish didn’t happen?	Substance Use Disorder (CIDI-SAM for DSM-III-R)	1136	261	875	0.410	0.960	0.754	0.845

Bradley et al, 2001⁴⁹	SASQ-Modified How often do you have six or more drinks on one occasion?	Alcohol-use disorder (DSM-III-R) or hazardous drinking (NAAA)	227	92	135	0.772	0.830	0.755	0.842

	SASQ-Modified Maximum number of drinks per occasion	Alcohol-use disorder (DSM-III-R) or hazardous drinking (NAAA)	227	92	135	0.587	0.770	0.635	0.732

Volk et al, 1997⁴⁸	CAGE: cut down question	Alcohol-use disorder (DSM-IV)	1333	205	1128	0.629	0.840	0.417	0.926

	CAGE: annoyed question	Alcohol-use disorder (DSM-IV)	1333	205	1128	0.239	0.930	0.383	0.871

	CAGE: guilty question	Alcohol-use disorder (DSM-IV)	1333	205	1128	0.371	0.900	0.402	0.887

	CAGE: eye-opener question	Alcohol-use disorder (DSM-IV)	1333	205	1128	0.210	0.950	0.434	0.869

Smith et al 2009⁵²	SASQ-Modified How many times in the past year have you had X or more drinks in a day?	Alcohol-use disorder (DSM-IV)	286	33	253	0.879	0.672	0.259	0.977

Two-question studies

Brown et al 2001⁵⁰	In the last year, have you ever drunk or used drugs more than you meant to? OR Have you felt you wanted or needed to cut down on your drinking or drug use in the last year?	Substance Use Disorder (CIDI-SAM for DSM-III-R)	1136	261	875	0.793	0.779	0.518	0.927

Vinson et al 2007³⁹	Q1 Recurrent drinking in situations in which it is physically hazardous, and Q2 drinking in larger amounts or over a longer period than intended	Alcohol-use disorder (DSM-IV)	623	126	498	0.944	0.819	0.569	0.983

NPV = negative predictive value. PPV = positive predictive value.