Table 1. Comparison of characteristics of patients with type 1 diabetes recruited between January 2012 and April 2013, from the Pediatrics Endocrinology Clinic at the University of Massachusetts Medical School (Continuous variables).

	Controls		Cases
Variable	(High HbA1c)		(Low HbA1c)
	n = 189		n = 34
	Mean ± SD	95% Confidence Interval	Mean ± SD	95% Confidence Interval	p value
Age (years)	15.41 ± 2.50	[15.04 to 15.77]	13.88 ± 2.34	[13.07 to 14.70]	0.001
HbA1c (%)	9.01 ± 1.19	[8.84 to 9.18]	7.14 ± 0.61	[6.93 to 7.36]	<0.001
Duration of Diabetes (years)	6.11 ± 4.18	[5.51 to 6.71]	3.81 ± 3.27	[2.67 to 4.95]	0.003
SMODA-A scores1
Collaboration with Parents	21.48 ± 10.30	[20.00 to 22.97]	23.19 ± 10.30	[19.60 to 26.79]	0.376
Care Activities	32.73 ± 5.87	[31.95 to 33.62]	34.84 ± 6.28	[32.64 to 37.03]	0.076
Problem Solving	14.21 ± 3.91	[13.66 to 14.79]	13.26 ± 4.51	[11.69 to 14.83]	0.253
Communication	18.06 ± 5.44	[17.28 to 18.84]	18.74 ± 6.14	[16.59 to 20.88]	0.551
Goals	15.31 ± 3.65	[14.89 to 15.89]	15.66 ± 4.92	[13.94 to 17.37]	0.698

¹ SMODA-A questions offer four choices between 0 and 3. Independent dimension scores will vary between 0 and 39 for “Collaboration with parents” (13 questions), between 0 and 45 for “Care activities” (15 questions), between 0 and 30 for “Communication” (10 questions) and between 0 and 21 for both “Problem solving” and “Goals” (7 questions each). Higher scores indicate more/better performance for each dimension.