Critical appraisal:Pastorino U, Rossi M, Rosato V, Marchianò A, Sverzellati N, Morosi C, et al 2012

Critical Appraisal

Article being appraised

Pastorino U, Rossi M, Rosato V, Marchianò A, Sverzellati N, Morosi C, et al. Annual or biennial CT screening versus observation in heavy smokers: 5-year results of the MILD trial. Eur J Cancer Prev 2012 May;21(3):308-15 Available from: http://www.ncbi.nlm.nih.gov/pubmed/22465911.

Applicable clinical question

In people at risk of lung cancer, does population based CT screening reduce mortality?

Key Facts

Study Design

randomised controlled trial

Number of Patients:

4099

Includes an economic evaluation

no

Evidence ratings

Level of evidence

II

Risk of bias

Moderate risk of bias

Comments:

Show/Hide Risk of bias assessment

Risk of bias assessment: randomised controlled trial

Was the trial double-blinded?

Trial was double-blinded but may have limitations (eg method of blinding inappropriate, tablet vs injection with no double-dummy, different treatment schedules, side-effects may unblind)

or
single-blinded (eg outcomes assessed blind, objective outcomes, no revealing side-effects).

Was the treatment allocation schedule concealed?

Adequately concealed (e.g. central randomisation, numbered or coded bottles, drugs prepared by pharmacy).

Were all randomised participants included in the analysis?

No exclusions or survival analysis used with all subjects included (>95% follow-up for all groups).

The field below is not considered when calculating the risk of bias rating

How was the allocation schedule generated?

Adequate (e.g. random number table, computer random generator, coin tossing, card shuffling)

Size of effect

4	Reason for decision: Both lung cancer specific mortality rates and total mortality rates between control, biennial and annual LDCT screening did not reach a significant difference, with p value of 0.21 and 0.13 respectively.

Relevance of evidence

1	Additional comments: lung cancer specific mortality and all causes mortality were both reported.

Result of appraisal

Included

Comments

The authors stated that this trial is under powered to detect LDCT screening benefit in the order of 10%.

Other useful information from this trial are 1. Selective use of PET decreases surgery for benign nodules to ~9%. 2. Element of overdiagnosis suggested by the annual versus biennial LDCT data. 3. The early pilot data and mortality curve with 10 years follow up did not suggest a protective effect of long term LDCT screening.

Completed by

Associate Professor Eddie Lau FRANZCR, FAANMS

This appraisal has been completed.