Table 1

Examples of statements found in the objectives and conclusions sections of abstracts of observational studies published in The BMJ in 2018 and their corresponding assigned category

Assigned categoryAbstract objectivesAbstract conclusionsComment
 Consistently causal‘…assess the effectiveness of…’‘Little evidence was found of a direct impact of…’When discussing associations, words like effect, contribution or role are similar to cause and then (direct) impact and effect will be their consequence.
‘To determine the effect of … in …’‘…has led to risk…’
‘To describe the contributions of…’‘… an important role in …’
‘To evaluate the impact of …’‘…impacts are…’
‘To investigate whether improving adherence to …’‘…the beneficial effect of improved…’Evaluates taking an action ‘improving adherence’ and concludes that the effect is beneficial.
‘…benefit of … in reducing … risk’‘… is an overlooked risk factor for …’Evaluates how a given intervention can reduce the risk of an outcome and then labels it as an ‘overlooked risk factor’.
‘To determine outcomes and safety of…’‘… is at least as effective and safe as …’Evaluates and determines that a certain intervention is as safe as the comparator.
‘to quantitatively decompose this joint association to … only, to … only, and to their interaction’.‘…excess risk of…These findings suggest that most cases of … could be prevented by …’Suggests interest in direct and indirect effect, that is, mediation analysis, and concludes consequently.
Consistently not causal (associations)‘…is associated with …compared with…’‘…is associated with …compared with…’Describes associations without labelling them as causal or prediction.
‘To describe trends in…’‘…rates were high during the study period of … with the highest rates in … vs …’Limits to describe frequency.
‘To assess how often …’‘One in … adults … were …’
‘To examine the association between…’‘…could increase … confirmation of these findings are warranted, preferably in an intervention setting’.Suggests further research to determine the nature of the association.
‘…compared with…is associated with…’‘Additional studies, with long term follow-up, are needed to investigate the effects of…’
Consistently not causal (prediction)‘To develop and validate a set of practical prediction tools that reliably estimate the outcome of…’‘…prediction models reliably estimate the outcome…’Describes developing and validating prediction models.
‘To prospectively validate the … algorithm to …’‘…accurately classified…’
Inconsistent‘…evaluate safety of…’‘…associated with…’Phrasing the objective as causal and limiting to describing an association in the conclusion.
‘…analyse the effect of…’
‘…critical determinant…’
‘…association with…’‘…is safe…’Phrasing the objective as just to explore an association and presenting a causal claim in the conclusion.
‘… had no substantial effect on long term survival…’
‘… was determined by… may be largely explained by…’
‘… was found to be the safest drug, with reduced risks of…’
‘These results emphasise the benefit of…’
‘…association with…’‘…tackling all these risk factors might substantially…’Phrasing the objective and conclusion as if just to assess an association but then suggesting to take action given the findings.
‘…Targeting … prevention strategies among these patients should be considered’.
‘Systematically addressing … may be an important public health strategy to reduce the incidence of’
‘…present findings encourage the downward revision of such guidelines …’