A group-randomized caries-prevention trial for Cree children: baseline measures compared

Objectives: This randomized clinical trial will test the effectiveness of motivational interviewing to control caries in young Cree children in Eeyou Istchee, the Cree territory of northern Quebec, Canada. Mothers' baseline characteristics will be reported. Methods: Expectant or new Cree mothers were recruited from the 5 test and 4 control communities. At recruitment, the data collected included maternal demographics, dental knowledge, oral hygiene practices and dental health of other children. Results: 272 mothers (131 test, 141 control) were recruited over 2-years. The mean (SD) age of recruited women was 25.6 (6.1) years; stage of pregnancy was 20.2 (10.7) weeks; 65.1% of subjects had other children and 42.0% of these mothers had a child who had had a tooth extracted. The mean (SD) score out of 5 for the knowledge questions was 3.0 (1.3); 92.3% of mothers brushed their teeth with toothpaste >1x/day; 72.7% of mothers had seen a dentist <2 years ago. Comparisons of test and control women determined that the arms of the trial were well-balanced on most but not all measures: mean age in the two groups was 25.5 versus 25.6 years; stage of pregnancy was 22.4 versus 17.7 weeks; percentage of mothers with other children was 64.3 versus 65.7; percentage of mothers having a child who previously had an extraction were 34.1 versus 48.9; mean knowledge scores were 3.1 versus 2.9; percentage of mothers brushing their own teeth was 92.3 versus 92.2; percentage who had seen a dentist <2 years ago was 71.5 versus 73.8. Because of the group imbalances on certain variables, it will be necessary to control baseline variables in the analyses of treatment effects. Conclusions: The results illustrate the high likelihood that some baseline variables will be unevenly split in group-randomized trials when the number of groups is small. Control of baseline variables in the analysis will usually be required in this type of trial. This study was supported by CIHR-RCT Grant FRN 67817.