Table 3. Mean±standard deviation of overall 12-Item Zarit Burden Interview score and analysis of variance for Perceived Stress Scale, São Carlos, SP, Brazil, 2014 (n=341).

	1st quartile	2nd quartile	3rd quartile	4th quartile	F statistic (p-value)
PSS*	2.9±3.4 (n=84)	6.0±6.2 (n=89)	7.0±7.3 (n=83)	13.4±10.6 (n=85)	30.55 (< 0.001)

^*one-way ANOVA with Tukey's post hoc test: 1^st quartile < 2^nd quartile < 3^rd quartile < 4^th quartile; PSS: perceived stress scale.