. Author manuscript; available in PMC: 2015 Apr 1.

Published in final edited form as: Behav Modif. 2014 Dec 29;39(1):8–42. doi: 10.1177/0145445514561318

Table 5.

Study Determinants and Ratings (Group Design).

Study	Study design	Sample Attrition (low, high)	Baseline equivalence	Evaluation result
Gest and Gest (2005)	RCT	Total: 7/24 (29%); treatment: 2/12 (17%); comparison: 5/12 (41%); difference: 24%; sample attrition: High	No	DNMS
Lane, Fletcher, Carter, Dejud, and DeLorenzo (2007)	RCT	Total: 1/25 (4%); treatment: 0%; comparison: 1/12 (8%); difference: 8%; sample attrition: Low	Not required for determining study rating	MS
Nelson, Stage, Epstein, and Pierce (2005)	RCT	Total: 21/84 (25%); treatment: 17/64 (27%); comparison: 4/20 (20%); difference: 7%; sample attrition: Low	Not required for determining study rating	MS
O’Shaughnessy and Swanson (2000)	RCT	No attrition; sample attrition: Low	Not required for determining study rating	MS
Strayhorn and Bickel (2002)	RCT	Total: 3/27 (11%); treatment: 1/10 (10%); comparison: 2/17 (12%); difference: 2%; sample attrition: Low	Not required for determining study rating	MS
Feldman (1981)	Quasi	Not required for determining study rating	No	DNMS
Scruggs and Osguthorpe (1986)	Quasi	Not required for determining study rating	No	DNMS

Note. RCT = Randomized Controlled Trial; DNMS = Does not meet WWC Standards; MS = Meets WWC Standards; MSWR = Meets WWC Standards With Reservations; WWC = What Works Clearinghouse.