Table 2

 Coding scheme

Primary code and subcodesDescription
CPS, Cancer Prevention Survey.
CausationDoes smoking cause cost?
Economic research in generalAre the methods of economic research legitimate? Are the results of economic analyses credible?
Analysis of cofactors and/or confoundersDoes the model take confounding and cofactors into account appropriately?
Issue framingIs the issue a medical one or a statistical one?
Death benefitDoes the model take into account the savings to health insurance, social security, and pension plans that result from premature death from smoking-related illness? This was a way of trying to cast the model in a framework that considers tobacco as contributing to an overall benefit rather than a cost
    • Lifetime v annual costsIs the model cast in a lifetime cost framework thus considering savings that accrue from early death?
    • Incidence v annual costs(Same argument as above, but with different terminology.) Is the model cast in an incidence-based cost framework, thus considering savings that accrue from early death?
Sample selectionDid the models use the appropriate dataset?
    • CPS IIAny discussion of the merits of the CPS II data
Scientific judgmentWhat role did subjective judgment play in development of the models?
Use of statistical models
    • Missing dataWas missing data handled appropriately?
    • Statistical reliability/ validityWere the models used statistically reliable and valid?
    • Statistical scienceIs the science of statistics a legitimate one?
    • Statistical significanceWere the variables of interest statistically significant?
    • Omitted variablesWere any variables that should have been included omitted from the models?