Despite overwhelming evidence, Big Tobacco just won't admit plain packaging has drastically reduced smoking rates. Thankfully, their hollow denials now lack any impact, writes Simon Chapman.

Thursday July 17, 2014 is unlikely to be a date that the global tobacco industry will ever forget.

At 1am in the Australian morning an embargo was lifted on a set of numbers that drove a stake deep into the heart of Big Tobacco's best efforts to deny that plain tobacco packaging had made any impact on Australians' smoking.

The Australian Institute of Health and Welfare (AIHW) released the results of its latest national survey of drug, alcohol and tobacco use, involving 23,855 people. These surveys have been conducted every three years since 1991, when 24.3 per cent of Australians aged 14 and over smoked on a daily basis.

In December 2013, this figure had almost halved to 12.8 per cent, the lowest in the world after Sweden, which has 11.8 per cent daily smoking in addition to 12.1 per cent (20.7 per cent of men) using smokeless snus tobacco daily.

Moreover, the percentage fall between 2010 and 2013 was a record 15.2 per cent. The average percentage decline across the nine triennial surveys since 1991 had been 7.6 per cent, with the previous biggest fall being 11 per cent.

So what was in play that might have caused such a dive? Other than the routine twice-yearly CPI tax increases in each of 2011, 2012 and 2013, bans on point-of-sale retail displays, a continuation of anti-smoking campaigning throughout the period in question, and measures like smoke-free restaurants and pubs that have been in place for many years, the elephant-in-the-room explanatory variable was the implementation of plain packaging in December 2012.

Together with an almost continuous national news diet of debate about the policy throughout much of the three years in question, no other policy or program presents as a plausible candidate.

In the weeks before this data bombshell exploded, The Australian newspaper ran a campaign involving three front-page stories, and a full-page of articles by journalists and contributors, some of whom are affiliated with the IPA. They drew on internal tobacco industry data that was never made available for public scrutiny.

This mystery data purported to claim a 0.3 per cent increase in consumption following plain packs. The Australian Treasury quietly released tobacco customs and excise data showing a fall of 3.4 per cent in 2013 relative to 2012 when tobacco plain packaging was introduced.

The Australian Bureau of Statistics also released data on expenditure on tobacco for the December 2012 ($3.508 billion) and the March 2013 ($3.405 billion) quarters, showing plain packaging was followed by a 2.9 per cent fall in consumption.

The timing of The Australian's campaign coincided with a final consultation period in England preceding a final decision on a stated intention to introduce plain packs in that country.

July 17 unleashed some of the most desperate straw-clutching from the industry and its blogosphere errand boys I have ever seen.

Imperial Tobacco and Philip Morris opened the batting, claiming there was no change in the long-term downward trend. In a press release BAT, like Imperial, said the fall was "in line with historical trends". It wasn't. It was the biggest percentage fall ever recorded since the surveys commenced.

Next, they highlighted the impact of the 2010 tax rise. There had been a 25 per cent tobacco tax increase in early May 2010, but the first five months impact of that rise coincided with the data collection period (April 29 to September 14, 2010) for the previous AIHW survey, published in 2011.

Then they referred to the December 2013 12.5 per cent tax rise as an influence. But data collection for the 2011-2013 AIHW report occurred between July 31 and December 1, 2013 - the day an extra 12.5 per cent tobacco tax was introduced. It could therefore have not influenced the data showing the fall.

They also explained that the 12.8 per cent prevalence figure was a fudge because it was only daily smokers. It didn't include "casual" smokers, whom we were told would lift the true "incidence figure" to 16.4 per cent. (And note that BAT apparently doesn't know the basic difference between incidence and prevalence.)

But they couldn't even get that right. The AIHW data showed 12.8 per cent daily, 1.4 per cent weekly, and 1.6 per cent less than weekly, making 15.8 per cent. Pathetically, here was BAT desperate to claim as their own those who admit to smoking a cigarette once in a blue moon. Note that the prevalence of those who smoked at any frequency (daily, weekly and less than weekly) fell by almost 13 per cent between 2010 and 2013, another record fall, more than double the average three-yearly declines over the previous 20 years.

Then they whined that because the data included those aged under 17 (where only 3.4 per cent smoked daily), this would have artificially deflated the "true" figure. This ignores that the 14 years and over figure had been standard in every year since the surveys commenced in 1991, and that between the 2010 and 2013 surveys, daily smoking fell in every age group above 18 years, with the exception of those aged over 70, which increased slightly from 5.6 per cent to 5.8 per cent.

However, a tiny ray of hope remained. A tobacco-loving English blogger noticed that in the 12-17 year age group (the principal target of plain packaging legislation) the percentage of daily smokers actually rose from 2.5 per cent to 3.4 per cent.

The jubilant blogger took the trouble to construct a bold graph that emphasised this massive uplift. But he failed to tell his readers that for five of 10 data cells that made up the figures, the standard error was more than 50 per cent ("too unreliable for general use") and another two cells with lower standard errors "should be used with caution").

Citi, the global market investment advisers, was in no doubt about the meaning of the data, saying it provided "the best data" to support the British government's imminent decision to legislate plain packs and that the data would "substantially undermine" the tobacco industry's argument that there was no good evidence that plain packaging would achieve its stated aims.

Like Monty Python's Black Knight talking about "just a flesh wound" after losing all four limbs, this is not likely to be the last round of denials from Big Tobacco. But following their hollow denials of impact, they are now little more than laugh-a-minute spectator sport.

Simon Chapman AO is professor of public health at Sydney University. His book Removing the Cancer Emperor's Clothes: tobacco plain packaging in Australia will be published later this year by Sydney University Press. View his full profile here.