. Author manuscript; available in PMC: 2019 Sep 1.

Published in final edited form as: J Public Health Dent. 2018 May 12;78(4):321–328. doi: 10.1111/jphd.12275

Table 3.

Comparisons of DFS Counts and Adjusted Caries Increments for Iowa Fluoride Subjects for Different Levels of Explanatory Variables, Stratified by Age (based on n=392)

DFS Count		Age 9¹			Age 13			Age 17

Variable	Description	n	Mean (SD)	p-value²	n	Mean (SD)	p-value²	n	Mean (SD)	p-value²
Sex	Males	177	0.38 (0.90)	0.235	179	0.79 (1.81)	0.133	177	2.49 (3.58)	0.078
Sex	Females	199	0.60 (1.27)	0.235	203	1.28 (2.30)	0.133	195	3.35 (4.40)	0.078

Income Category in 2007	< $60,000 per year	117	0.68 (1.26)	0.016	119	1.35 (2.17)	0.017	117	3.68 (4.58)	0.016
Income Category in 2007	>= $60,000 per year	259	0.41 (1.04)	0.016	263	0.92 (2.05)	0.017	255	2.60 (3.74)	0.016

Mother’s Education in 2007	< 4-Year College Degree	189	0.60 (1.23)	0.066	191	1.34 (2.42)	0.004	182	3.70 (4.64)	<0.001
Mother’s Education in 2007	4-Year College Degree or More	187	0.40 (0.99)	0.066	191	0.77 (1.67)	0.004	190	2.22 (3.24)	<0.001

Adjusted Caries Increment		Age 9¹			Age 13			Age 17

Variable	Description	n	Mean (SD)	p-value²	n	Mean (SD)	p-value²	n	Mean (SD)	p-value²

Sex	Males	177	0.38 (0.90)	0.235	179	0.51 (1.51)	0.070	177	1.70 (2.62)	0.241
Sex	Females	199	0.60 (1.27)	0.235	203	0.77 (1.53)	0.070	195	2.07 (3.04)	0.241

Income Category in 2007	< $60,000 per year	117	0.68 (1.26)	0.016	119	0.80 (1.55)	0.074	117	2.21 (2.92)	0.050
Income Category in 2007	>= $60,000 per year	259	0.41 (1.04)	0.016	263	0.58 (1.51)	0.074	255	1.75 (2.81)	0.050

Mother’s Education in 2007	< 4-Year College Degree	189	0.60 (1.23)	0.066	191	0.82 (1.81)	0.018	182	2.22 (3.13)	0.012
Mother’s Education in 2007	4-Year College Degree or More	187	0.40 (0.99)	0.066	191	0.48 (1.16)	0.018	190	1.58 (2.52)	0.012

Prevalence at age 9 is the same as the age 9 increment

Wilcoxon Rank-Sum Test – tests for a difference between two groups with continuous, non-normal data