Plaque Index, Oral Hygiene Habits, and Depressive Symptomatology as Predictors of Clinical Attachment Loss: A Pilot Study

Table 5

Descriptive statistics and normality test in the sample of 35 dental patients.

Sample	Variable	Descriptive statistics						Shapiro–Wilk’s test
		Min	Max	Sk	ZSk	K3	ZK3	W	df
Dental patient sample	BDI−II	0	13	0.162	0.391	−1.228	−1.483	0.922	35	0.016
	OHHS	0.25	2.50	0.275	0.663	−0.077	−0.093	0.959	35	0.215
	CAL	3.80	5.42	0.515	1.243	0.965	1.165	0.957	35	0.192
	PI	2	3.72	0.181	0.436	−0.947	−1.144	0.971	35	0.463
Mental health patient sample	BDI−II	14	50	0.699	1.456	−0.059	−0.062	0.932	26	0.086
	OHHS	0.25	3.50	1.045	2.176	1.676	1.744	0.905	26	0.020
	CAL	3.21	4.78	−0.536	−1.116	−0.044	−0.046	0.958	26	0.353
	PI	2.13	3.63	0.366	0.762	−0.699	−0.728	0.955	26	0.301
General population sample	BDI−II	0	11	0.902	1.983	−0.251	−0.276	.868	29	0.002
	OHHS	0.50	3.37	0.847	1.861	0.127	0.139	.928	29	0.050
	CAL	0	6	−0.882	−1.940	−0.547	−0.601	.828	29	<0.001
	CAL^2	0	36	0.003	0.006	−0.578	−0.636	.939	29	0.095
	PI	0.83	3.56	−0.244	−0.537	−1.014	−1.114	.954	29	0.235

Note. Variables: BDI-II = total score in Beck Depression Inventory-II, OHHS = total score in Hygiene Habits Scale, CAL = clinical attachment loss, CAL² = clinical attachment loss values squared to correct negative skewness, and PI = plaque index. Statistics: Min = minimum, Max = maximum, Sk = coefficient of skewness based on central moments, Z_Sk = standardized value of the coefficient of skewness, K₃ = excess kurtosis, Z_K3 = standardized value of excess kurtosis, W = Shapiro–Wilk’s testing statistic, df = degree of freedom, and value = probability value under null hypothesis that empirical distribution follows a normal distribution.