When Things Are Not as They Appear: Assessing the Adequacy of Cluster Randomization When Outcome Events Are Rare at Baseline

Table 4

Standardized regression coefficients for GLAT scores¹ predicting youth reported behavior over the past 6 months.

Youth self-reported:	Baseline	6 months	12 months	18 months	24 months	36 months	36 month prevalence
Risk behaviors:
Suspended from school	0.31	−0.31	0.12	0.28	0.16	−0.21
Carried a knife to use as a weapon	−0.21	−0.32	−0.50	−0.54*	−0.42	−0.61*
Carried a gun to use as a weapon	−0.07	−0.48	−0.25	0.19	−0.34	−0.59*
Involved in a physical fight	−0.02	0.06	−0.43	−0.47	−0.64**	−0.52
Smoked cigarettes	0.37	−0.53*	0.14	−0.34	0.06	−0.43
Drank alcoholic beverages	−0.34	−0.13	−0.22	−0.36	−0.30	−0.01
Used marijuana	−0.10	−0.09	−0.59*	−0.50	−0.35	0.01
Tried any form of cocaine	0.05	0.23	.027	0.09	−0.54*	−0.63*
Sold or delivered drugs	−0.04	−0.43	−0.18	−0.63	−0.64**	−.17
Ever had sex	−0.70**	−0.64*	−0.54*	−0.65**	−0.73*	−.063*
Consistent condom use	0.00	0.09	−0.46	0.06	−0.07	−0.16
Seen relative:
Drink alcohol	0.10	−0.31	−0.27	0.33	−.07	0.00	−.25
Smoke marijuana	−0.50	−0.45	−0.42	−0.69*	−55*	−0.59*	−0.70**
Use cocaine	−0.45	−0.64**	−0.62*	−0.70**	−0.19	−0.46	−0.69**
Sell drugs	−0.51	−0.58*	−0.59*	−0.54*	−0.56	−0.39	−0.63*
Seen neighbor:
Drink alcohol	−0.40	−0.39	−0.62*	−.70**	−0.74**	−0.71**	−0.75**
Smoke marijuana	−0.46	−0.39	−0.53*	−0.65*	−0.74**	−0.74**	−0.73**
Use cocaine	−0.49	−0.54*	−0.67**	−0.76**	−0.66**	−0.58*	−0.80**
Sell drugs	−0.43	−0.70**	−0.53*	−0.70**	−0.67**	−0.75**	−0.76**

¹Passing rates of the 2005 English Grade Level Achievement Test (GLAT) (scores of C or better) by school.
* 𝑃<0.05, **𝑃<0.01.