Limits...
Comparison of different approaches to estimating age standardized net survival.

Lambert PC, Dickman PW, Rutherford MJ - BMC Med Res Methodol (2015)

Bottom Line: We compare lifetable-based estimates (Ederer II), a new unbiased method based on inverse probability of censoring weights (Pohar Perme) and model-based estimates.However, both the Ederer II and modelling approaches have some advantages over the Pohar Perme method in terms of greater precision, particularly for longer-term follow-up (10 and 15 years).We have also shown advantages in using the more traditional and modelling methods.

View Article: PubMed Central - PubMed

Affiliation: Department of Health Sciences, University of Leicester, University Road, Leicester, LE1 7RH, UK. paul.lambert@le.ac.uk.

ABSTRACT

Background: Age-standardized net survival provides an important population-based summary of cancer survival that appropriately accounts for differences in other-cause mortality rates and standardizes the population age distribution to allow fair comparisons. Recently, there has been debate over the most appropriate method for estimating this quantity, with the traditional Ederer II approach being shown to have potential bias.

Methods: We compare lifetable-based estimates (Ederer II), a new unbiased method based on inverse probability of censoring weights (Pohar Perme) and model-based estimates. We make the comparison in a simulation setting; generating scenarios where we would expect to see a large theoretical bias.

Results: Our simulations demonstrate that even in relatively extreme scenarios there is negligible bias in age-standardized net survival when using the age-standardized Ederer II method, modelling with continuous age or using the Pohar Perme method. However, both the Ederer II and modelling approaches have some advantages over the Pohar Perme method in terms of greater precision, particularly for longer-term follow-up (10 and 15 years).

Conclusions: Our results show that, when age-standardizing, concern over bias with the traditional methods is unfounded. We have also shown advantages in using the more traditional and modelling methods.

No MeSH data available.


Related in: MedlinePlus

Scenario 2: Scatter Plot of Estimated Externally Age Standardized Net Survival for the 1000 Different Estimates for each of the Methods. The True Value is Shown by a Reference Line
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4537569&req=5

Fig6: Scenario 2: Scatter Plot of Estimated Externally Age Standardized Net Survival for the 1000 Different Estimates for each of the Methods. The True Value is Shown by a Reference Line

Mentions: Table 4 shows the bias, MSE and coverage for scenario 2 with Figs. 5 and 6 showing scatter plots of the estimates from each simulation for internal and external standardization respectively. One would expect more bias for the Ederer II method in this scenario since variation by age in excess mortality continues for the whole study follow-up. This can be seen by the fact that the Ederer II all age estimate (internal) and the Brenner method (external) gives biased estimates. For example, a 1.91 and 2.80 percentage point difference for external age standardization for 10 and 15 years respectively. However, the bias for Ederer II using traditional age standardization is less than 0.3 percentage points. There is some bias for the model-based grouped age estimate at a 0.94 and 1.10 percentage point difference for 10 and 15 years respectively. Coverage is reasonable for the Pohar Perme, Ederer II traditional age standardized and model-based continuous age. As for scenario 1 the Pohar Perme method has a higher MSE reflecting more variation in the estimate.Fig. 5


Comparison of different approaches to estimating age standardized net survival.

Lambert PC, Dickman PW, Rutherford MJ - BMC Med Res Methodol (2015)

Scenario 2: Scatter Plot of Estimated Externally Age Standardized Net Survival for the 1000 Different Estimates for each of the Methods. The True Value is Shown by a Reference Line
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4537569&req=5

Fig6: Scenario 2: Scatter Plot of Estimated Externally Age Standardized Net Survival for the 1000 Different Estimates for each of the Methods. The True Value is Shown by a Reference Line
Mentions: Table 4 shows the bias, MSE and coverage for scenario 2 with Figs. 5 and 6 showing scatter plots of the estimates from each simulation for internal and external standardization respectively. One would expect more bias for the Ederer II method in this scenario since variation by age in excess mortality continues for the whole study follow-up. This can be seen by the fact that the Ederer II all age estimate (internal) and the Brenner method (external) gives biased estimates. For example, a 1.91 and 2.80 percentage point difference for external age standardization for 10 and 15 years respectively. However, the bias for Ederer II using traditional age standardization is less than 0.3 percentage points. There is some bias for the model-based grouped age estimate at a 0.94 and 1.10 percentage point difference for 10 and 15 years respectively. Coverage is reasonable for the Pohar Perme, Ederer II traditional age standardized and model-based continuous age. As for scenario 1 the Pohar Perme method has a higher MSE reflecting more variation in the estimate.Fig. 5

Bottom Line: We compare lifetable-based estimates (Ederer II), a new unbiased method based on inverse probability of censoring weights (Pohar Perme) and model-based estimates.However, both the Ederer II and modelling approaches have some advantages over the Pohar Perme method in terms of greater precision, particularly for longer-term follow-up (10 and 15 years).We have also shown advantages in using the more traditional and modelling methods.

View Article: PubMed Central - PubMed

Affiliation: Department of Health Sciences, University of Leicester, University Road, Leicester, LE1 7RH, UK. paul.lambert@le.ac.uk.

ABSTRACT

Background: Age-standardized net survival provides an important population-based summary of cancer survival that appropriately accounts for differences in other-cause mortality rates and standardizes the population age distribution to allow fair comparisons. Recently, there has been debate over the most appropriate method for estimating this quantity, with the traditional Ederer II approach being shown to have potential bias.

Methods: We compare lifetable-based estimates (Ederer II), a new unbiased method based on inverse probability of censoring weights (Pohar Perme) and model-based estimates. We make the comparison in a simulation setting; generating scenarios where we would expect to see a large theoretical bias.

Results: Our simulations demonstrate that even in relatively extreme scenarios there is negligible bias in age-standardized net survival when using the age-standardized Ederer II method, modelling with continuous age or using the Pohar Perme method. However, both the Ederer II and modelling approaches have some advantages over the Pohar Perme method in terms of greater precision, particularly for longer-term follow-up (10 and 15 years).

Conclusions: Our results show that, when age-standardizing, concern over bias with the traditional methods is unfounded. We have also shown advantages in using the more traditional and modelling methods.

No MeSH data available.


Related in: MedlinePlus