Table 2.
Descriptive statistics and paired statistical comparisons for human topography and biomarker outcome measures from participants (n=34 unless specified) smoking the RWP in three configurations: control, bubble diffuser and electric
| Mean±SD | P values for statistical comparison* | ||||
|---|---|---|---|---|---|
| Control | Bubble diffuser | Electric | Bubble diffuser versus control | Electric versus control | |
| Topography measures | |||||
| Number of puffs | 70.9±37.8 | 73.4±37.2 | 92.5±39.8 | ns | P<0.01 |
| Puff volume (L) | 0.65±0.27 | 0.73±0.37 | 0.90±0.43 | ns | P<0.0001 |
| Puff duration (s) | 4.4±2.1 | 4.3±2.3 | 5.1±2.2 | ns | P<0.10 |
| Puff interval (s) | 26.2±14.4 | 28.2±17.3 | 22.6±16.1 | ns | ns |
| Puff peak flow (L/min) | 15.8±4.8 | 17.1±5.4 | 17.7±5.2 | ns | P<0.01 |
| Puff average flow (L/min) | 10.1±3.8 | 11.5±4.6 | 11.9±4.4 | P<0.05 | P<0.001 |
| Total puff volume (L) | 41.7±25.8 | 48.7±35.8 | 82.6±63.8 | ns | P<0.0001 |
| Duration of smoking (min) | 31.6±14.5 | 32.5±12.1 | 38.5±26 | ns | ns |
| Exposure measures | |||||
| Environmental CO (mg/session) | 980.5±368.5 | 1012±274.8 | 1.7±3.1 (n=25)† | ns | P<0.0001 |
| Exhaled CO boost (ppmv) | 51.7±19.9 (n=33)‡ | 56.5±36.1 (n=33)‡ | 0.1±1.3 | ns | P<0.0001 |
| Exhaled benzene boost (ppmv) | 8.5±5.4 (n=31)§ | 8.4±4.9 (n=32)§ | −0.1±0.3 | ns | P<0.0001 |
| Plasma nicotine (ng/mL) | 12.2±12.7 | 13.7±13.6 | 7.5±6.7 | ns | P<0.05 |
| Heart rate boost (bpm) | 13.9±10.6 (n=29)¶ | 15.8±11.5 (n=33)¶ | 9.4±9.7 (n=33)¶ | ns | P<0.10 |
| Maximum heart rate (bpm) | 112±15.2 (n=29)¶ | 113±13.1 (n=33)¶ | 112±10.9 (n=33)¶ | ns | P<0.05 |
| Tobacco and charcoal consumption | |||||
| Tobacco consumed (g) | 2.1±0.7 (n=33)** | 2.2±0.8 (n=34) | 2.0±0.8 (n=33)** | ns | ns |
| Tobacco consumed (%) | 21.0±7.1 (n=33)** | 22.2±8.0 (n=34) | 20.4±8.2 (n=33)** | ns | ns |
| Charcoal consumed (g) | 5.8±1.1 (n=34) | 6.0±0.9 (n=33)*** | - | ns | ns |
| Charcoal consumed (%) | 55.5±11.0 (n=34) | 57.0±10.5 (n=33)*** | - | ns | ns |
Both control and bubble diffuser use charcoal heating of the tobacco, whereas electric uses electric heating.
Statistical comparisons were made between control and each configuration. Bolded entry indicates significant difference from control at a p value of 0.10 or smaller. The p values were adjusted for multiple testing.
The CO monitor was inoperable during nine electric smoking sessions.
Exhaled CO not collected for one control and one bubble diffuser session.
Exhaled benzene not collected for three control and two bubble diffuser sessions.
Heart rate data collection file was incomplete for five controls, one bubble diffuser and one electric session.
Final tobacco weight not recorded for one control and one electric session.
Final charcoal weight not recorded for one bubble diffuser session.
bpm, beats per minute; CO, carbon monoxide; n, sample size; ns, not significant; ppmv, parts per million by volume.