Evidence map›Paper›PMID 34275444›Full record

Trial reportBMC public health2021

Cigarette pack size and consumption: an adaptive randomised controlled trial.

Ilse Lee, Anna K M Blackwell, Michelle Scollo, Katie De-Loyde, Richard W Morris, Mark A Pilling, Gareth J Hollands, Melanie Wakefield, Marcus R Munafò, Theresa M Marteau

Open access · goldAbstract readRandomized Controlled Trial
PubMed Full text at PMC Publisher
In one paragraph

Trial report in BMC public health, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed, 1 pooled it
0.4field-weighted citation impact, top 42% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed, 1 synthesis or guideline pooled it, 3 citations in OpenAlex.

  1. Small/Kiddie Cigarette Packaging Size and Its Impact on Smoking: A Systematic Review.International journal of environmental research and public health · 2022
    Pooled it
  2. Trial
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

10 authors at 3 institutions in 2 countries.

Ilse LeeBehaviour and Health Research Unit, University of Cambridge, Cambridge, CB2 0SR, UK.
Anna K M BlackwellSchool of Psychological Science, University of Bristol, 12a Priory Road, Bristol, BS8 1TU, UK.
Michelle ScolloCentre for Behavioural Research in Cancer, Cancer Council Victoria 615 St Kilda Rd, Melbourne, Vic, 3004, Australia.
Katie De-LoydeSchool of Psychological Science, University of Bristol, 12a Priory Road, Bristol, BS8 1TU, UK.
Richard W MorrisDepartment of Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.
Mark A PillingBehaviour and Health Research Unit, University of Cambridge, Cambridge, CB2 0SR, UK.
Gareth J HollandsBehaviour and Health Research Unit, University of Cambridge, Cambridge, CB2 0SR, UK.
Melanie WakefieldCentre for Behavioural Research in Cancer, Cancer Council Victoria 615 St Kilda Rd, Melbourne, Vic, 3004, Australia.
Marcus R MunafòSchool of Psychological Science, University of Bristol, 12a Priory Road, Bristol, BS8 1TU, UK.
Theresa M MarteauBehaviour and Health Research Unit, University of Cambridge, Cambridge, CB2 0SR, UK. tm388@medschl.cam.ac.uk.ORCID 0000-0003-3025-1129
University of Bristol · GBUniversity of Cambridge · GBCancer Council Victoria · AU

Funding

Wellcome TrustWellcome Trust 206853/Z/17/Z
6 · The paper itself

Abstract

backgroundObservational evidence suggests that cigarette pack size - the number of cigarettes in a single pack - is associated with consumption but experimental evidence of a causal relationship is lacking. The tobacco industry is introducing increasingly large packs, in the absence of maximum cigarette pack size regulation. In Australia, the minimum pack size is 20 but packs of up to 50 cigarettes are available. We aimed to estimate the impact on smoking of reducing cigarette pack sizes from ≥25 to 20 cigarettes per pack.

methodA two-stage adaptive parallel group RCT in which Australian smokers who usually purchase packs containing ≥25 cigarettes were randomised to use only packs containing either 20 (intervention) or their usual packs (control) for four weeks. The primary outcome, the average number of cigarettes smoked per day, was measured through collecting all finished cigarette packs, labelled with the number of cigarettes participants smoked. An interim sample size re-estimation was used to evaluate the possibility of detecting a meaningful difference in the primary outcome.

resultsThe interim analysis, conducted when 124 participants had been randomised, suggested 1122 additional participants needed to be randomised for sufficient power to detect a meaningful effect. This exceeded pre-specified criteria for feasible recruitment, and data collection was terminated accordingly. Analysis of complete data (n = 79) indicated that the mean cigarettes smoked per day was 15.9 (SD = 8.5) in the intervention arm and 16.8 (SD = 6.7) among controls (difference - 0.9: 95%CI = - 4.3, 2.6).

conclusionIt remains unclear whether reducing cigarette pack sizes from ≥25 to 20 cigarettes reduces cigarette consumption. Importantly, the results of this study provide no evidence that capping cigarette pack sizes would be ineffective at reducing smoking. The limitations identified in this study can inform a more efficient RCT, which is urgently required to address the dearth of experimental evidence on the impact of large cigarette pack sizes on smoking.

trial registrationhttps://doi.org/10.1186/ISRCTN34202533.

Indexed as

Tobacco IndustryTobacco ProductsAustraliaHumansProduct LabelingProduct PackagingAdaptive designCigarette packagingPack sizeTobacco control

Identifiers

PMID34275444
PMCPMC8286601
OpenAlexW3161410625

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.