Table 1.

Demographic characteristics of the cohort at baseline

Demographic characteristic	Cohort (N = 78)
Mean age [y (SD; R)]	36 (10.16; 18–61)
Ethnic background
Persian [% (n)]	65.4 (51)
Azeri [% (n)]	16.7 (13)
Baloch [% (n)]	15.4 (12)
Marriage
First [% (n)]	41.0 (32)
Second [% (n)]	10.3 (8)
Temporary [% (n)]	3.8 (3)
Able to read and write [% (n)]	78.2 (61)
Occupation in month before registration
Home duties [% (n)]	52.6 (41)
Unemployed [% (n)]	25.6 (20)
Employed [% (n)]	19.2 (15)
Proportion who have ever used opium [% (n)]	69.2 (54)
Mean age at first use of opium [y (SD; R)]	25 (8.39; 13–48)
Proportion who have ever used heroin [% (n)]	87.2 (68)
Mean age at first use of heroin [y (SD; R)]	28 (9.51; 9–56)
Current heroin user at registration [% (n)]	48.7 (38)
Smoking as main route of heroin administration [% (n)]	88.5 (69)
Mean duration of drug problems [y (SD; R)]*	10.5 (9.9; 0–40)

Note:

^*Refers to the drug problems measured by the drug dependence questions of the International Statistical Classification of Diseases and Related Health Problems, tenth revision (see Table 3).

Abbreviations: R, range; SD, standard deviation; y, years.