Table 5.

Opening rates, sample size, and P values by media channel for demographic subgroups.

Characteristic			Message opening, %			Sample size, n				P value
		Email		SMS		Email	SMS
Age (years)
	50-55	65.3		50.2		32,836	16,801		<.001
	55-60	64.5		50.9		10,551	6846		<.001
	60-65	66.5		51.2		11,220	7758		<.001
	65-70	67.6		51.3		8356	6271		<.001
	70-74	67.7		48.3		6773	5570		<.001
SESa
	1-3	59.5		39.6		3897	7093		<.001
	4-6	62.6		49.3		27,563	23,642		<.001
	7-10	68.9		58.5		38,174	12,433		<.001
Gender
	Female	65.5		53.2		41,267	24,051		<.001
	Male	66.4		46.9		28,469	19,195		<.001
Overall			65.9		50.4	69,777		43,271		<.001

^aSES: socioeconomic status. This is an index defined by the Central Bureau of Statistics (CBS), ranging from 1 to 10, where 1 reflects the weakest status and 10 the highest.