Table 3.
Estimates of change in total HDL-C (mmol/l) following quitting a
| Factor | Level | N b |
Unweighted analysis |
Inverse-variance weighted analysis |
||
|---|---|---|---|---|---|---|
| Mean (95% CI) | p c | Mean (95% CI) | p c | |||
| Overall |
|
94 |
0.107 (0.085 to 0.128) |
<0.001 |
0.060 (0.044 to 0.075) |
<0.001 |
|
Univariate models |
|
|
|
|
|
|
| Periodd |
<3 weeks |
21 |
0.102 (0.047 to 0.157) |
0.04 |
0.100 (0.032 to 0.169) |
<0.001 |
| |
3 to <6 |
21 |
0.102 (0.063 to 0.141) |
|
0.082 (0.042 to 0.123) |
|
| |
6 to <13 |
20 |
0.157 (0.119 to 0.194) |
|
0.131 (0.094 to 0.168) |
|
| |
13 to <27 |
11 |
0.107 (0.057 to 0.158) |
|
0.108 (0.061 to 0.155) |
|
| |
27 to <52 |
1 |
0.100 (−0.068 to 0.268) |
|
0.094 (−0.221 to 0.409) |
|
| |
52+ weeks |
20 |
0.065 (0.027 to 0.102) |
|
0.041 (0.026 to 0.057) |
|
| Time quite |
<3 weeks |
23 |
0.101 (0.050 to 0.152) |
NS |
0.083 (0.030 to 0.137) |
0.006 |
| |
3 to <6 |
20 |
0.115 (0.075 to 0.155) |
|
0.112 (0.069 to 0.154) |
|
| |
6 to <13 |
22 |
0.145 (0.109 to 0.181) |
|
0.111 (0.075 to 0.148) |
|
| |
13 to <27 |
9 |
0.099 (0.042 to 0.156) |
|
0.072 (0.036 to 0.109) |
|
| |
27 to <52 |
4 |
0.088 (0.003 to 0.173) |
|
0.058 (−0.004 to 0.121) |
|
| |
52+ weeks |
16 |
0.062 (0.020 to 0.105) |
|
0.040 (0.023 to 0.057) |
|
|
Models adjusted for time quit |
|
|
|
|
|
|
| Max Agef |
<50 years |
8 |
0.124 (0.047 to 0.201) |
NS |
0.161 (0.072 to 0.250) |
NS |
| |
50-70 years |
28 |
0.107 (0.071 to 0.144) |
|
0.065 (0.038 to 0.093) |
|
| |
>70 years |
58 |
0.094 (0.063 to 0.125) |
|
0.080 (0.057 to 0.104) |
|
| Sex |
Male |
46 |
0.090 (0.060 to 0.121) |
NS |
0.073 (0.046 to 0.099) |
NS |
| |
Female |
30 |
0.139 (0.094 to 0.184) |
|
0.123 (0.061 to 0.186) |
|
| |
Combined |
18 |
0.095 (0.052 to 0.138) |
|
0.078 (0.050 to 0.107) |
|
| Continent |
N America |
49 |
0.121 (0.082 to 0.160) |
NS |
0.055 (0.024 to 0.087) |
NS |
| |
Europe |
30 |
0.110 (0.075 to 0.146) |
|
0.096 (0.062 to 0.130) |
|
| |
Asia |
13 |
0.067 (0.016 to 0.118) |
|
0.081 (0.050 to 0.112) |
|
| |
Australia |
2 |
0.026 (−0.099 to 0.152) |
|
0.018 (−0.179 to 0.215) |
|
| Timingg |
<1990 |
26 |
0.119 (0.077 to 0.160) |
NS |
0.049 (0.016 to 0.082) |
0.08 |
| |
1990-1999 |
58 |
0.100 (0.071 to 0.129) |
|
0.088 (0.065 to 0.110) |
|
| |
2000+ |
10 |
0.071 (0.012 to 0.130) |
|
0.077 (0.040 to 0.114) |
|
| Study type |
Observational |
16 |
0.094 (0.031 to 0.157) |
NS |
0.086 (0.057 to 0.115) |
NS |
| |
RCT |
16 |
0.093 (0.042 to 0.145) |
|
0.090 (0.057 to 0.123) |
|
| |
Other |
62 |
0.108 (0.073 to 0.143) |
|
0.067 (0.040 to 0.093) |
|
| Product smoked |
Any |
16 |
0.102 (0.056 to 0.148) |
NS |
0.103 (0.072 to 0.133) |
0.09 |
| |
Cigarettes |
67 |
0.102 (0.075 to 0.130) |
|
0.069 (0.047 to 0.091) |
|
| |
Cigarettes only |
11 |
0.095 (0.035 to 0.155) |
|
0.092 (0.054 to 0.129) |
|
| Validation of quitting |
Yes |
48 |
0.113 (0.077 to 0.149) |
NS |
0.088 (0.060 to 0.115) |
NS |
| |
No |
46 |
0.092 (0.059 to 0.125) |
|
0.075 (0.051 to 0.098) |
|
| Constraint on diet/exercise |
Stay same |
15 |
0.141 (0.089 to 0.193) |
0.09 |
0.191 (0.126 to 0.255) |
0.003 |
| |
Improve |
9 |
0.135 (0.076 to 0.193) |
|
0.064 (0.036 to 0.092) |
|
| |
No constraint |
70 |
0.087 (0.061 to 0.114) |
|
0.082 (0.066 to 0.099) |
|
| Baseline HDL-C |
1st tertile |
34 |
0.111 (0.070 to 0.151) |
NS |
0.101 (0.068 to 0.134) |
0.03 |
| |
2nd tertile |
25 |
0.131 (0.083 to 0.178) |
|
0.097 (0.048 to 0.147) |
|
| |
3rd tertile |
28 |
0.100 (0.064 to 0.135) |
|
0.084 (0.061 to 0.108) |
|
| |
unknown |
7 |
0.044 (−0.030 to 0.118) |
|
0.042 (0.010 to 0.073) |
|
| Baseline weight/BMIh |
1st tertile |
19 |
0.132 (0.066 to 0.199) |
NS |
0.154 (0.042 to 0.267) |
NS |
| |
2nd tertile |
28 |
0.073 (0.039 to 0.108) |
|
0.073 (0.048 to 0.098) |
|
| |
3rd tertile |
21 |
0.111 (0.060 to 0.163) |
|
0.112 (0.065 to 0.158) |
|
| |
unknown |
26 |
0.120 (0.083 to 0.156) |
|
0.076 (0.047 to 0.105) |
|
| Change in weight/BMIh |
1st tertile |
5 |
0.155 (0.077 to 0.232) |
NS |
0.161 (0.092 to 0.230) |
0.06 |
| |
2nd tertile |
29 |
0.076 (0.031 to 0.121) |
|
0.074 (0.022 to 0.125) |
|
| |
3rd tertile |
51 |
0.100 (0.073 to 0.128) |
|
0.065 (0.041 to 0.089) |
|
| |
unknown |
9 |
0.105 (0.041 to 0.170) |
|
0.104 (0.042 to 0.166) |
|
| Baseline LDL-C |
1st tertile |
17 |
0.067 (0.001 to 0.132) |
NS |
0.092 (0.045 to 0.139) |
NS |
| |
2nd tertile |
16 |
0.132 (0.063 to 0.201) |
|
0.084 (0.017 to 0.150) |
|
| |
3rd tertile |
17 |
0.085 (0.039 to 0.130) |
|
0.071 (0.028 to 0.113) |
|
| |
unknown |
44 |
0.110 (0.079 to 0.141) |
|
0.080 (0.054 to 0.106) |
|
| Baseline Triglycerides |
1st tertile |
26 |
0.134 (0.085 to 0.184) |
NS |
0.099 (0.017 to 0.181) |
NS |
| |
2nd tertile |
13 |
0.108 (0.059 to 0.157) |
|
0.099 (0.034 to 0.163) |
|
| |
3rd tertile |
24 |
0.075 (0.027 to 0.123) |
|
0.079 (0.044 to 0.114) |
|
| |
unknown |
31 |
0.096 (0.062 to 0.130) |
|
0.075 (0.050 to 0.099) |
|
| Baseline Systolic BP |
1st tertile |
8 |
0.079 (0.015 to 0.142) |
NS |
0.060 (0.006 to 0.115) |
NS |
| |
2nd tertile |
7 |
0.117 (0.046 to 0.188) |
|
0.096 (0.058 to 0.134) |
|
| |
3rd tertile |
5 |
0.066 (−0.016 to 0.148) |
|
0.090 (0.056 to 0.125) |
|
| |
unknown |
74 |
0.107 (0.079 to 0.135) |
|
0.075 (0.052 to 0.098) |
|
| Baseline Diastolic BP |
1st tertile |
8 |
0.079 (0.015 to 0.142) |
NS |
0.060 (0.006 to 0.115) |
NS |
| |
2nd tertile |
7 |
0.117 (0.046 to 0.188) |
|
0.096 (0.058 to 0.134) |
|
| |
3rd tertile |
5 |
0.066 (−0.016 to 0.148) |
|
0.090 (0.056 to 0.125) |
|
| unknown | 74 | 0.107 (0.079 to 0.135) | 0.075 (0.052 to 0.098) | |||
aSee Additional file 2 (Table A2-1) for data used on change and SE. Analyses are based on repeated measures analysis of variance using the Kenward-Roger method.
bNumber of estimates that the mean is based on.
cNS p≥0.1. For the overall analysis, this is based on a test for an increase following quitting. For the subgroup analysis, this tests for variation by subgroup level.
dPeriod between first measurement when smoking and second measurement when not smoking (using mean, median or midpoint where necessary).
eBest estimate of time since quit at second measurement.
fMaximum age of population at baseline.
gBased on year of start of study.
hUsing data for weight if both weight and BMI available (see Methods).