01.12.2013  Research article  Ausgabe 1/2013 Open Access
Quantitative summaries of treatment effect estimates obtained with network metaanalysis of survival curves to inform decisionmaking
 Zeitschrift:
 BMC Medical Research Methodology > Ausgabe 1/2013
Electronic supplementary material
Competing interests
Authors’ contributions
Background
Methods
Motivating example
Evidence base
Network metaanalysis
Results
Treatment effects and functional estimates
Outcome

DTIC

DTIC + IFN

DTIC + nonIFN

NonDTIC


Median survival

7.85

7.87

9.88

10.19

Expected survival (after all patients died) and 95% credible interval

12.61 (11.31, 14.13)

11.41 (8.44, 15.48)

16.11 (11.21, 23.14)

15.31 (9.17, 24.34)

Mean survival at 22 months and 95% credible interval

9.84 (9.13, 10.60)

9.61 (7.66, 11.72)

11.15 (8.88, 13.33)

11.23 (8.05, 13.99)

Graphical and numerical summaries of rank probabilities
Discussion
Advantages and disadvantages of different effect measures in relation to treatment ranking
Measure

Probability that a treatment is associated with:

Explicitly reflects time effect

Reflects cumulative effect over time

Requires baseline risk

Advantage

Disadvantage


Median survival

The greatest survival time when 50% patients are alive

No

Yes

Yes

Commonly used and clinically relevant; Easily summarized as statistic; May limit need for extrapolation;

Ignores what happens after 50% of subjects have experienced the event;

Expected survival

The greatest expected survival

No

Yes

Yes

Directly relevant for costeffectiveness; Easily summarized as statistic;

Sensitive to tail of distribution (may involve extrapolation); Does not illustrate timevarying results or time of greatest treatment effect; May not be as clinically relevant;

Mean survival at time t

Greatest mean survival (area under the curve) up until time t

No

Yes

Yes

Limits need for extrapolation if time t corresponds to followup time of trial with shortest duration; Easily summarized as statistic

May be difficult to interpret; Requires subjective selection of time t; Ignores tails of distribution and does not illustrate timevarying results;

Hazard (ratio) over time

The smallest hazard (ratio versus reference treatment) over time

Yes

No

Yes for hazard,

Directly relates to model and may help emphasize changes in treatment effect over time;

Does not capture cumulative effect of treatment over time; May lead to over interpretation near tail of distribution; Cannot be summarized as statistic (requires graphical illustration); May be more difficult to understand;

No for hazard ratio


Survival proportion over time (Cumulative hazard over time)

The greatest survival (proportion) over time

Yes

Yes

Yes

Highly intuitive and clinically relevant; Can be easily compared to data;

Cannot be summarized as statistic (requires graphical illustration);

Mean survival over time

Greatest mean survival (area under the curve) over time

Yes

Yes

Yes

Reflects a cumulative summary of survival proportions up until that time point, thereby deemphasizing tail of distribution;

Cannot be summarized as statistic (requires graphical illustration); May be more difficult to understand;
