Overall, there were 2,485 private and 2,685 public university students in our sample. In private universities 76.3% of males and 61.4% of females, and among public university students 72.7% of males and 49% of females were ever users of waterpipe. For both genders, the type of university matters for ever using waterpipe (p-values <0.05 and <0.001 respectively). Similarly, within age groups, the percentages of ever users are higher in the private universities (with the exception of the oldest age group) (Table 1).
Compared to public university students, a higher share of private university students has access to a car (51.7% versus 35.8%), live at home with family (51.6% versus 46.4%), rely on their families for financial support (71.5% versus 65.1%), and have sufficient income (51.9% versus 35.1%). For all categories of these socioeconomic variables (except for working to make a living), the type of university matters for ever using waterpipe (Table 1).
Private university students stated that waterpipe consumption is common among their friends. Compared to public university students, a lower share of private university students said that currently none of their friends use waterpipe (18% versus 24.6%). Moreover, a higher share of private than public university students are ever cigarette smokers (69.7% versus 63.6%) (Table 1).
Patterns of waterpipe smoking among respondents who have ever smoked waterpipe (n=1,699 in private, n=1,582 in public universities) are shown in Table 2. In this group, the majority (63.2% in private universities and 62.6% in public university) used it first when they were in ages 14-18 (p>0.05); 14.8% (in private universities) and 8.7% (in public university) of ever users stated that they smoked waterpipe within the last month (p<0.001).
Waterpipe is most often (>90%) used outside of home (at a narghile cafe or at other cafes, restaurants, or tea houses) and more than 85% of the students usually shared their waterpipe (p=0.101). Compared to public university students, more opportunities (a higher number of waterpipe offering venues) exist for private university students where they usually spend time (close to their university) (p<0.001) (Table 2).
More than half of the students in both types of institutions (59.2% and 60.9%) think that waterpipe is more harmful than cigarettes. Close to 20% think that they are equally harmful (p>0.05). Students enjoy waterpipe for several reasons. The sensory charms of waterpipe are important for youth. Respondents in private and public universities agreed that they enjoy the aroma (more than 75%), they find it pleasurable (51.8% and 42.7%), and enjoy that its smoke does not hurt throat (31.4% and 31.0%). Students also stated that they like waterpipe because it facilitates socialization (44.7% versus 33%, p<0.001), it can be shared with friends (31.0% versus 25.0%, p<0.001), and it makes conversation more fun (27.8% versus 22.7%, p=0.001). A higher share of private university (versus public university) students emphasized the feelings of enjoyment for waterpipe smoking (Table 2).
Among current users of waterpipe who revealed spending information (n=752), the average monthly spending on waterpipe was statistically significantly higher among private university students (42 TL) than among public university students (29.6 TL) (not tabulated).
Table 1: Demographics of survey participants by university type and waterpipe use status
|
Private
|
Public
|
p
|
|
Ever
|
Never
|
Total
|
Ever
|
Never
|
Total
|
|
|
%
|
%
|
n
|
%
|
%
|
%
|
n
|
%
|
|
Gender
|
|
|
|
|
|
|
|
|
|
Male
|
76.3
|
23.7
|
1,289
|
51.9
|
72.7
|
27.3
|
1,140
|
42.5
|
0.045
|
Female
|
61.4
|
38.6
|
1,196
|
48.1
|
49.0
|
51.0
|
1,545
|
57.5
|
<0.001
|
Age group
|
|
|
|
|
|
|
|
|
|
18-19
|
59.2
|
40.8
|
485
|
19.9
|
45.4
|
54.6
|
377
|
14.6
|
<0.001
|
20-21
|
66.4
|
33.6
|
1,010
|
41.4
|
56.7
|
43.3
|
1,057
|
40.8
|
<0.001
|
22-23
|
76.3
|
23.7
|
710
|
29.1
|
61.5
|
38.5
|
799
|
30.8
|
<0.001
|
24 or older
|
80.9
|
19.1
|
236
|
9.7
|
74.3
|
25.7
|
358
|
13.8
|
0.060
|
Has a car
|
|
|
|
|
|
|
|
|
|
Yes
|
73.1
|
26.9
|
1,126
|
51.7
|
67.7
|
32.3
|
895
|
35.8
|
0.008
|
No
|
64.3
|
35.7
|
1,052
|
48.3
|
54.4
|
45.6
|
1,607
|
64.2
|
<0.001
|
Living arrangement
|
|
|
|
|
|
|
|
|
|
In dormitory
|
65.5
|
34.5
|
837
|
36.3
|
49.7
|
50.3
|
927
|
36.5
|
<0.001
|
Lives alone
|
90.1
|
9.9
|
131
|
5.7
|
79.6
|
20.4
|
137
|
5.4
|
0.017
|
Lives with family
|
68.0
|
32.0
|
1,189
|
51.6
|
60.7
|
39.3
|
1,178
|
46.4
|
<0.001
|
Has roommate(s)
|
82.2
|
17.8
|
146
|
6.3
|
72.9
|
27.1
|
295
|
11.6
|
0.031
|
Source of income*
|
|
|
|
|
|
|
|
|
|
Family support
|
70.6
|
29.4
|
1,716
|
71.5
|
58.2
|
41.8
|
1,706
|
65.1
|
<0.001
|
Scholarship
|
60.4
|
39.6
|
490
|
20.4
|
51.6
|
48.4
|
543
|
20.7
|
0.004
|
Work
|
78.3
|
21.7
|
92
|
3.8
|
75.0
|
25.0
|
252
|
9.6
|
0.532
|
Perception of income sufficiency
|
|
|
|
|
|
|
|
|
Not sufficient
|
81.9
|
18.1
|
144
|
6.1
|
61.0
|
39.0
|
418
|
16.1
|
<0.001
|
Barely sufficient
|
73.7
|
26.3
|
982
|
41.9
|
60.4
|
39.6
|
1,265
|
48.8
|
<0.001
|
Sufficient
|
64.2
|
35.8
|
1,216
|
51.9
|
56.9
|
43.1
|
911
|
35.1
|
0.001
|
Waterpipe use among friends
|
|
|
|
|
|
|
|
|
Most or all
|
78.6
|
21.4
|
406
|
17.3
|
69.7
|
30.3
|
416
|
16.0
|
0.004
|
Some
|
70.7
|
29.3
|
1,513
|
64.6
|
62.4
|
37.6
|
1,538
|
59.3
|
<0.001
|
None
|
55.5
|
44.5
|
422
|
18.0
|
45.0
|
55.0
|
638
|
24.6
|
0.001
|
Cigarette smoking
|
|
|
|
|
|
|
|
|
|
Ever
|
85.9
|
14.1
|
1,732
|
69.7
|
79.6
|
20.4
|
1,707
|
63.6
|
<0.001
|
Never
|
30.4
|
69.6
|
753
|
30.3
|
23.3
|
76.7
|
978
|
36.4
|
0.001
|
Notes: The p-value refers to the chi-square test where the null hypothesis is no relationship between the type of the university and waterpipe use status.
(*) More than one income source could be selected.
Table 2. Patterns of waterpipe smoking among respondents who have ever smoked waterpipe
|
Private University
|
Public University
|
p-value
|
|
n
|
%
|
n
|
%
|
|
Age at first use
|
|
|
|
|
0.133
|
Younger than 14
|
171
|
10.1
|
133
|
8.4
|
|
Ages 14-18
|
1,074
|
63.2
|
990
|
62.6
|
|
Older than 18
|
454
|
26.7
|
459
|
29.0
|
|
Use within the last month
|
|
|
|
|
<0.001
|
Yes
|
253
|
14.8
|
137
|
8.7
|
|
No
|
1,454
|
85.2
|
1,445
|
91.3
|
|
Location of waterpipe use
|
|
|
|
|
0.303
|
At home only
|
21
|
3.8
|
26
|
5.7
|
|
Outside of home only
|
489
|
87.9
|
395
|
87.0
|
|
Both at home and outside of home
|
46
|
8.3
|
33
|
7.3
|
|
Number of waterpipe venues close by
|
|
|
|
|
<0.001
|
None
|
224
|
13.5
|
359
|
23.2
|
|
1-3 venues
|
677
|
40.8
|
593
|
38.3
|
|
4 or more venues
|
758
|
45.7
|
598
|
38.6
|
|
Waterpipe sharing (usually)
|
|
|
|
|
0.101
|
No
|
78
|
14.4
|
48
|
10.9
|
|
Yes
|
465
|
85.6
|
394
|
89.1
|
|
Reasons for waterpipe use*
|
|
|
|
|
|
Enjoy the aroma
|
1293
|
75.3
|
1197
|
75.5
|
0.911
|
Pleasurable
|
889
|
51.8
|
677
|
42.7
|
<0.001
|
Facilitates socialization
|
767
|
44.7
|
524
|
33.0
|
<0.001
|
Smoke does not hurt throat
|
539
|
31.4
|
492
|
31.0
|
0.818
|
Can be shared with friends
|
533
|
31.0
|
397
|
25.0
|
<0.001
|
Makes conversation more fun
|
478
|
27.8
|
360
|
22.7
|
0.001
|
Part of traditional culture
|
339
|
19.7
|
249
|
15.7
|
0.002
|
Makes nice visual in social media
|
306
|
17.8
|
285
|
18.0
|
0.912
|
Nice ambience and food
|
304
|
17.7
|
220
|
13.9
|
0.003
|
Shares in social media invoke curiosity
|
185
|
10.8
|
143
|
9.0
|
0.091
|
Waterpipe or cigarettes more harmful
|
|
|
|
|
0.335
|
Waterpipe is more harmful
|
935
|
59.2
|
915
|
60.9
|
|
Both are equally harmful
|
274
|
17.4
|
275
|
18.3
|
|
Cigarettes are more harmful
|
245
|
15.5
|
202
|
13.4
|
|
Do not know
|
125
|
7.9
|
110
|
7.3
|
|
Note: Sum of n’s may differ across categories since not all questions are answered by all participants. (*) More than one reason could be selected.
The estimates presented in Table 3 show that in both private and public universities, being male and being older were positively associated with ever use of waterpipe. In the public university, having access to a car increased the risk (OR 1.367). Compared to living in the dormitory, living alone (OR 3.187 and 2.132) or having roommate(s) (OR 1.922 and 1.673) increased the risk in both types of universities. Living with family increased risk in the public university (OR 1.258). Compared to living on a scholarship, being financially supported by the family increased risk in the private universities (OR 1.658) and earning income from work substantially increased the risk for all students (OR 1.751 and 2.101).
Table 3. Ever smoked waterpipe: Logistic regression estimates (Odds ratios)
|
Private university
|
Public university
|
All
|
Interaction effect with “Private”
|
Private university
|
|
|
1.574***
|
|
|
|
|
(0.105)
|
|
Base category: Female
|
|
|
|
|
Male
|
2.231***
|
2.499***
|
2.359***
|
0.893
|
|
(0.223)
|
(0.237)
|
(0.161)
|
(0.123)
|
Base category: Ages 18-19
|
|
|
|
|
Ages 20-21
|
1.334**
|
1.666***
|
1.502***
|
0.801
|
|
(0.167)
|
(0.222)
|
(0.136)
|
(0.146)
|
Ages 22-23
|
2.307***
|
1.870***
|
2.039***
|
1.233
|
|
(0.324)
|
(0.264)
|
(0.201)
|
(0.246)
|
Ages 24 or older
|
2.410***
|
2.482***
|
2.389***
|
0.971
|
|
(0.523)
|
(0.448)
|
(0.325)
|
(0.274)
|
Base category: No car
|
|
|
|
|
Has a car
|
1.116
|
1.367***
|
1.237***
|
0.816
|
|
(0.116)
|
(0.137)
|
(0.0890)
|
(0.118)
|
Base category: Lives in dormitory
|
|
|
|
|
Home with family
|
0.996
|
1.258**
|
1.153*
|
0.792
|
|
(0.113)
|
(0.125)
|
(0.0854)
|
(0.120)
|
Lives alone
|
3.187***
|
2.132***
|
2.557***
|
1.495
|
|
(1.032)
|
(0.530)
|
(0.496)
|
(0.610)
|
Has roommate(s)
|
1.922***
|
1.673***
|
1.708***
|
1.149
|
|
(0.470)
|
(0.269)
|
(0.226)
|
(0.336)
|
Base category: Scholarship
|
|
|
|
|
Income source: Family Support
|
1.658***
|
1.126
|
1.320***
|
1.473**
|
|
(0.204)
|
(0.120)
|
(0.105)
|
(0.240)
|
Income source: Work
|
1.751*
|
2.101***
|
2.072***
|
0.833
|
|
(0.554)
|
(0.458)
|
(0.370)
|
(0.320)
|
Observations
|
2184
|
2352
|
4536
|
4536
|
Notes: The first two columns show estimates of odds ratios for private and public university students separately. The third column shows the estimates for the entire sample, adding the “Private” dummy variable to the regression. The last column shows the estimates of the interaction terms (when all explanatory variables are interacted with the “Private” dummy). Standard errors of coefficient estimates are shown in parentheses. * p<0.10, ** p<0.05, *** p<0.01.
In Table 3, as shown in the third column, which shows the estimates for the entire sample, being in a private university increases the risk of ever using (OR 1.574), after controlling for other factors. In the fourth column, all explanatory variables are interacted with the “Private” dummy and only the estimates of the interaction terms are presented. Private university students who rely financially on family support are at a higher risk (OR 1.473), relative to public university students. The other interaction terms are statistically insignificant, but it is noteworthy that being female or having a car has higher risk in public universities, whereas living alone or having roommate(s) has higher risk in private universities, although at low levels of statistical significance.
Table 4: Waterpipe and cigarette use status by university type and age at first use
|
Private university
|
Public university
|
|
Students who tried waterpipe
|
|
|
Students who tried waterpipe
|
|
|
|
Before 18
|
After 18
|
Total
|
Before 18
|
After 18
|
Total
|
|
n
|
% *
|
n
|
% *
|
n
|
%**
|
n
|
% *
|
n
|
% *
|
n
|
%**
|
Never user of either
|
|
|
|
|
524
|
22.0
|
|
|
|
|
750
|
29.1
|
Past user
|
|
|
|
|
711
|
29.9
|
|
|
|
|
849
|
32.9
|
Waterpipe only
|
105
|
61.8
|
65
|
38.2
|
170
|
7.2
|
114
|
60.6
|
74
|
39.4
|
188
|
7.3
|
Cigarette onlyna
|
-
|
|
-
|
|
154
|
6.5
|
-
|
|
-
|
|
245
|
9.5
|
Both
|
271
|
70.0
|
116
|
30.0
|
387
|
16.3
|
268
|
64.4
|
148
|
35.6
|
416
|
16.1
|
Current user
|
|
|
|
|
1142
|
48.0
|
|
|
|
|
978
|
38.0
|
Waterpipe only
|
117
|
68.0
|
55
|
32.0
|
172
|
7.2
|
94
|
69.1
|
42
|
30.9
|
136
|
5.3
|
Cigarette only
|
546
|
77.2
|
161
|
22.8
|
707
|
29.7
|
477
|
75.0
|
159
|
25.0
|
636
|
24.7
|
Dual user
|
206
|
78.3
|
57
|
21.7
|
263
|
11.1
|
170
|
82.5
|
36
|
17.5
|
206
|
8.0
|
Total
|
1245
|
|
454
|
|
2377
|
|
1123
|
|
459
|
|
2577
|
|
Notes: *row percentage, ** column percentage, na: not available
Among private university students 22% are never users, 29.9% are past users, and 48% are current users of waterpipe (Table 4). The percentages are 29.1%, 32.9%, and 38% for public university students. In the overall, a higher share of students tried waterpipe before age 18 than after. Among ever users of waterpipe, 29.5% of private university students tried it after age 18 ((65+116+55+57) /(170+387+172+263) = 293/992) and 31.7% of public university students tried it after age 18 ((74+148+42+36)/(188+416+136+206)=300/946).
Among ever users of waterpipe in private universities (170+387+172+263=992), 70.5% tried it before age 18 and 46.2% (323/699) of those who tried before age 18 are current users. Among ever users of waterpipe in public universities, 68.3% tried it before age 18, and 40.9% (264/646) of those who tried before age 18 are current users.
In order to investigate the characteristics of students who try waterpipe after age 18 (at university), we estimate the same logistic regression in a sample of students who have never smoked waterpipe before age 18 (Table 5). Male (OR 1.743) and older students (OR 3.419-7.5) are at higher risk of use after age 18. These groups are at greater risk in public universities than in private universities (interaction terms ORs<1). Women are at higher risk in private universities. Although not precisely estimated, having a car (OR 1.152) increases the risk for all students, but more so for public university students (interaction term OR=0.852<1). Living alone (OR 2.638) or having roommate(s) (OR 1.675) increases the risk mainly in private universities, whereas living with family (OR 1.287) increases the risk in the public university. Being financially supported by the family (OR 1.353) increases risk in the private universities, while earning income from work (OR 2.645) substantially increases the risk in the public university.
Table 5. Logistic regression of ever using waterpipe (after excluding students who tried waterpipe before age 18)
|
Private university
|
Public university
|
All
|
Interaction effect with “Private”
|
Private university
|
|
|
1.698***
|
|
|
|
|
(0.162)
|
|
Base category: Female
|
|
|
|
|
Male
|
1.469***
|
2.032***
|
1.743***
|
0.723*
|
|
(0.202)
|
(0.278)
|
(0.168)
|
(0.140)
|
Base category: Ages 18-19
|
|
|
|
|
Ages 20-21
|
2.639***
|
5.680***
|
3.419***
|
0.465*
|
|
(0.562)
|
(1.870)
|
(0.599)
|
(0.182)
|
Ages 22-23
|
5.063***
|
9.355***
|
6.102***
|
0.541
|
|
(1.129)
|
(3.101)
|
(1.095)
|
(0.216)
|
Ages 24 or older
|
5.997***
|
11.83***
|
7.500***
|
0.507
|
|
(1.780)
|
(4.220)
|
(1.587)
|
(0.235)
|
Base category: No car
|
|
|
|
|
Has a car
|
1.069
|
1.254
|
1.152
|
0.852
|
|
(0.154)
|
(0.179)
|
(0.117)
|
(0.173)
|
Base category: Lives in dormitory
|
|
|
|
Lives with family
|
0.909
|
1.287*
|
1.096
|
0.706
|
|
(0.144)
|
(0.191)
|
(0.118)
|
(0.154)
|
Lives alone
|
2.638**
|
1.206
|
1.761**
|
2.188
|
|
(1.039)
|
(0.422)
|
(0.449)
|
(1.152)
|
Has roommate(s)
|
1.675*
|
1.501*
|
1.559**
|
1.116
|
|
(0.521)
|
(0.327)
|
(0.273)
|
(0.424)
|
Base category: Scholarship
|
|
|
|
|
Income source: Family Support
|
1.353*
|
1.235
|
1.279**
|
1.095
|
|
(0.230)
|
(0.200)
|
(0.148)
|
(0.257)
|
Income source: Work
|
1.508
|
2.645***
|
2.244***
|
0.570
|
|
(0.608)
|
(0.747)
|
(0.508)
|
(0.280)
|
Observations
|
1076
|
1366
|
2442
|
2442
|
Notes: See Notes to Table 3.
A breakdown into four categories (never smokers, waterpipe smokers, cigarette smokers, and dual smokers) yields additional evidence to support our results. Appendix Table A1 shows that ever users of waterpipe, cigarettes, or both, have different characteristics from never users. Similar to the results in Tables 3 and 5, Appendix Table A2 shows that compared to never smokers, women in private universities were at higher risk of waterpipe use than men (RRR for men 0.651). For public university students, having a car increased the risk of being a dual user (RRR 0.738). Being older (RRR 1.5-2.7 relative to ages 18-19), living alone or having roommate(s) (RRR 2.2-3.18 relative to living in dorm), relying on family support, having earnings from own work (RRR 1.4-2.3 times relative to having a scholarship) increased the risk of being a dual user for both private and public university students. Having family as the main source of financial support increased the risk of using tobacco products among private university students more than it did for public university students.