Table 7.
Generalized Estimating Equations (GEE) estimation of trend in cigarette expenditure share in smokers’ household income in China, 2006–2015.
| Coef. | Std. Err. | z | P>|z| | (95% Conf. Int.) | ||
|---|---|---|---|---|---|---|
| 2006 | −0.01 | 0.00 | −2.16 | 0.03 | −0.02 | 0.00 |
| 2009 | −0.01 | 0.00 | −4.09 | 0.00 | −0.02 | −0.01 |
| 2011–2012 | −0.03 | 0.00 | −6.95 | 0.00 | −0.03 | −0.02 |
| 2013–2015 | −0.05 | 0.00 | −11.15 | 0.00 | −0.06 | −0.04 |
| Constant | 0.17 | 0.01 | 22.31 | 0.00 | 0.16 | 0.19 |
Note: Coef. = Coefficient estimates; Std. Err. = Standard Error of Coefficient estimates; z = z statistic; P>|z| = p-value of z statistic; 95% Conf. Int. = 95% Confidence Interval of the Coefficient estimates. The reference survey wave is Wave 2 (2007–2008). Estimates were adjusted for age, gender, household income status, individual education and employment status, price tiers of cigarettes in last purchase, and city of residence of respondents.