Letter: Could smoking reduction have other causes?

From Tamsin Nicholson, Glasgow, UK

You say that plain packets help Australian smokers quit (4 March, p 6). But couldn't the decrease in Australian smokers after the advent of plain packaging be caused by other facets of an anti-smoking campaign?

It may be a “record decline”, but is it dramatically different from the decrease in smoking since the anti-smoking campaign began?

The editor writes:
• Several readers asked similar questions. The introduction of plain packaging coincided with an abrupt steepening in the trend line for declining smoking rates.