Table 1.
Number of Days of Hookah Tobacco Smoking in the Last Month, by Wave
| All Participants | Hookah Users | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Wave/Month | N | Mean | SD | Median | Range | n | Mean | SD | Median | IQ Range |
| 1 August | 483 | 2.0 | 7.0 | 0 | 0–100 | 140 | 7.0 | 11.7 | 3 | 2–5 |
| 2 September | 466 | 0.3 | 1.7 | 0 | 0–25 | 51 | 3.1 | 4.2 | 2 | 1–3 |
| 3 October | 458 | 0.2 | 1.0 | 0 | 0–10 | 50 | 2.1 | 2.2 | 1 | 1–2 |
| 4 November | 456 | 0.1 | 0.7 | 0 | 0–10 | 29 | 2.0 | 1.9 | 1 | 1–2 |
| 5 December | 435 | 0.1 | 0.6 | 0 | 0–7 | 26 | 2.0 | 1.5 | 1.5 | 1–2 |
| 6 January | 441 | 0.2 | 1.0 | 0 | 0–15 | 36 | 2.2 | 2.8 | 1 | 1–2 |
| 7 February | 441 | 0.1 | 0.5 | 0 | 0–5 | 20 | 2.1 | 1.3 | 2 | 1–3 |
| 8 March | 427 | 0.2 | 0.8 | 0 | 0–9 | 35 | 2.1 | 1.9 | 1 | 1–3 |
| 9 April | 411 | 0.2 | 0.8 | 0 | 0–10 | 32 | 2.2 | 2.1 | 1 | 1–3 |
| 10 June | 402 | 0.2 | 0.9 | 0 | 0–10 | 36 | 2.3 | 2.0 | 2 | 1–3 |
| 11 July | 390 | 0.2 | 0.9 | 0 | 0–10 | 35 | 2.3 | 1.9 | 2 | 1–4 |
| 12 August | 400 | 0.2 | 1.1 | 0 | 0–15 | 43 | 2.3 | 2.6 | 1 | 1–2 |
| 13 september | 424 | 0.3 | 1.0 | 0 | 0–10 | 54 | 2.4 | 1.9 | 2 | 1–3 |
Note. IQ = Interquartile. N for each wave is the number of participants who completed that wave's survey and did not leave the hookah question blank. Wave 1 frequency of use covers lifetime prior to college entry; for waves 2–13, frequency of use covers the last month only. The right-hand panel (“Hookah Users”) provides descriptive statistics for only those participants who reported hookah use during that particular wave. Among all participants, the interquartile range is not shown in the table because it was 0–0 for all waves except wave 1, for which it was 0–1.