Table 4.

Differences in PMBS and AMBS items on the Ingestion Problems and Side Effects factor overall (N=239) and by age at study visit. PMBS-AMBS < 0 indicates higher barriers on AMBS.

Ingestion Problems and Side Effects Factor Item: PMBS-AMBS Difference	Total (N=239)		Ages 8–11 (N=33)		Ages 12–21 years (N=206)
	Mean ± SD	p-value	Mean ± SD	p-value	Mean ± SD	p-value
Medicine is hard to swallow	−0.23±1.07	0.001	−0.48±1.06	0.013	−0.19±1.06	0.011
Has too many side effects*	−0.12±1.2	0.11	−0.30±0.95	0.077	−0.09±1.2	0.28
Don’t like what it does to my appearance*	−0.06±1.3	0.49	−0.30±1.3	0.19	−0.02±1.3	0.83
Medicine tastes bad*	−0.31±1.4	<0.001	0.06±1.4	0.81	−0.38±1.3	<0.001
Too many pills to take*	−0.06±1.4	0.47	−0.52±1.3	0.024	0.01±1.4	0.92
Don’t want others to notice*	0.09±1.6	0.36	−0.15±1.3	0.52	0.14±1.6	0.24

Each PMBS and AMBS item is rated on a 5-point scale from 1 (strongly disagree, low barrier) to 5 (strongly agree, high barrier). Factor scores are presented as the mean of the factor item ratings.

^*Data not available for all subjects. Missing values: Has too many side effects=2, Don’t like what it does to my appearance=1, Medicine tastes bad=4, Too many pills to take=2, Don’t want others to notice=5.

p-values are from paired t-tests of the hypotheses that there is no difference between PMBS and AMBS item scores within each patient.