Question

Corsi et al. (2007) conducted a study of the factors mediating whether injection drug users enter a drug treatment program. In the sample of 491 drug users, 38.1% were single; 27.5% were married or had a partner; and 34.4% were divorced, separated, or widowed. Of the 194 drug users in this group who entered a treatment program, 67 were single, 66 were married or had a partner, and 61 were divorced, widowed, or separated. Based on these data, would one say that marital status is associated with entry into a treatment program?

Answer 1

Observed
	Single	Married	Others	total
Treatment	67	66	61	194
No treatment	120	69	108	297
Total	187	135	169	491

Expected frequencies, Ei = sum(rowi)*sum(coli)/total

Expected
	Single	Married	Others
Treatment	73.914	53.350	66.736
No treatment	113.157	81.675	102.168

Test statistic, chi-square = sum((Oi - Ei)^2/Ei) = 6.84

p-value = 0.0327

as p-value is less than the significance level of 0.05, reject H0

There evidence to conclude that marital status is associated with entry into a treatment program