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External validation and calibration of IVFpredict: a national prospective cohort study of 130,960 in vitro fertilisation cycles.

Smith AD, Tilling K, Lawlor DA, Nelson SM - PLoS ONE (2015)

Bottom Line: IVFpredict had markedly better calibration and higher diagnostic accuracy, with calibration plot intercept of 0.040 (95% CI: 0.017-0.063) and slope of 0.932 (95% CI: 0.839-1.025) compared with 0.080 (95% CI: 0.044-0.117) and 1.419 (95% CI: 1.149-1.690) for the Templeton model.Updating the models to reflect improvements in live birth rates since the models were developed enhanced their performance, but IVFpredict remained superior.External validation in a large population cohort confirms IVFpredict has superior discrimination and calibration for informing patients, clinicians and healthcare policy makers of the probability of live birth following IVF.

View Article: PubMed Central - PubMed

Affiliation: Medical Research Council Integrative Epidemiology Unit, the University of Bristol, Bristol, United Kingdom; School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.

ABSTRACT

Background: Accurately predicting the probability of a live birth after in vitro fertilisation (IVF) is important for patients, healthcare providers and policy makers. Two prediction models (Templeton and IVFpredict) have been previously developed from UK data and are widely used internationally. The more recent of these, IVFpredict, was shown to have greater predictive power in the development dataset. The aim of this study was external validation of the two models and comparison of their predictive ability.

Methods and findings: 130,960 IVF cycles undertaken in the UK in 2008-2010 were used to validate and compare the Templeton and IVFpredict models. Discriminatory power was calculated using the area under the receiver-operator curve and calibration assessed using a calibration plot and Hosmer-Lemeshow statistic. The scaled modified Brier score, with measures of reliability and resolution, were calculated to assess overall accuracy. Both models were compared after updating for current live birth rates to ensure that the average observed and predicted live birth rates were equal. The discriminative power of both methods was comparable: the area under the receiver-operator curve was 0.628 (95% confidence interval (CI): 0.625-0.631) for IVFpredict and 0.616 (95% CI: 0.613-0.620) for the Templeton model. IVFpredict had markedly better calibration and higher diagnostic accuracy, with calibration plot intercept of 0.040 (95% CI: 0.017-0.063) and slope of 0.932 (95% CI: 0.839-1.025) compared with 0.080 (95% CI: 0.044-0.117) and 1.419 (95% CI: 1.149-1.690) for the Templeton model. Both models underestimated the live birth rate, but this was particularly marked in the Templeton model. Updating the models to reflect improvements in live birth rates since the models were developed enhanced their performance, but IVFpredict remained superior.

Conclusion: External validation in a large population cohort confirms IVFpredict has superior discrimination and calibration for informing patients, clinicians and healthcare policy makers of the probability of live birth following IVF.

No MeSH data available.


Inclusion/exclusion criteria and formation of the validation sample.
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pone.0121357.g001: Inclusion/exclusion criteria and formation of the validation sample.

Mentions: There were 132,796 eligible IVF cycles that took place in the UK between 2008 and 2010. It was not possible to calculate a predicted probability of live birth for 1.4% of these cycles, due to missing information on duration of infertility or patient age greater than 50 years. There were a remaining 130,960 cycles available for validation; details of the formation of the validation sample are given in Fig. 1. Table 1 shows the characteristics of the treatment cycles in this study. Over half (51.7%) of cycles involved ICSI, and the proportion of cycles involving donor eggs increased with female age. There were 33,553 live births, giving a successful live birth rate of 25.6% per cycle in this cohort.


External validation and calibration of IVFpredict: a national prospective cohort study of 130,960 in vitro fertilisation cycles.

Smith AD, Tilling K, Lawlor DA, Nelson SM - PLoS ONE (2015)

Inclusion/exclusion criteria and formation of the validation sample.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390202&req=5

pone.0121357.g001: Inclusion/exclusion criteria and formation of the validation sample.
Mentions: There were 132,796 eligible IVF cycles that took place in the UK between 2008 and 2010. It was not possible to calculate a predicted probability of live birth for 1.4% of these cycles, due to missing information on duration of infertility or patient age greater than 50 years. There were a remaining 130,960 cycles available for validation; details of the formation of the validation sample are given in Fig. 1. Table 1 shows the characteristics of the treatment cycles in this study. Over half (51.7%) of cycles involved ICSI, and the proportion of cycles involving donor eggs increased with female age. There were 33,553 live births, giving a successful live birth rate of 25.6% per cycle in this cohort.

Bottom Line: IVFpredict had markedly better calibration and higher diagnostic accuracy, with calibration plot intercept of 0.040 (95% CI: 0.017-0.063) and slope of 0.932 (95% CI: 0.839-1.025) compared with 0.080 (95% CI: 0.044-0.117) and 1.419 (95% CI: 1.149-1.690) for the Templeton model.Updating the models to reflect improvements in live birth rates since the models were developed enhanced their performance, but IVFpredict remained superior.External validation in a large population cohort confirms IVFpredict has superior discrimination and calibration for informing patients, clinicians and healthcare policy makers of the probability of live birth following IVF.

View Article: PubMed Central - PubMed

Affiliation: Medical Research Council Integrative Epidemiology Unit, the University of Bristol, Bristol, United Kingdom; School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.

ABSTRACT

Background: Accurately predicting the probability of a live birth after in vitro fertilisation (IVF) is important for patients, healthcare providers and policy makers. Two prediction models (Templeton and IVFpredict) have been previously developed from UK data and are widely used internationally. The more recent of these, IVFpredict, was shown to have greater predictive power in the development dataset. The aim of this study was external validation of the two models and comparison of their predictive ability.

Methods and findings: 130,960 IVF cycles undertaken in the UK in 2008-2010 were used to validate and compare the Templeton and IVFpredict models. Discriminatory power was calculated using the area under the receiver-operator curve and calibration assessed using a calibration plot and Hosmer-Lemeshow statistic. The scaled modified Brier score, with measures of reliability and resolution, were calculated to assess overall accuracy. Both models were compared after updating for current live birth rates to ensure that the average observed and predicted live birth rates were equal. The discriminative power of both methods was comparable: the area under the receiver-operator curve was 0.628 (95% confidence interval (CI): 0.625-0.631) for IVFpredict and 0.616 (95% CI: 0.613-0.620) for the Templeton model. IVFpredict had markedly better calibration and higher diagnostic accuracy, with calibration plot intercept of 0.040 (95% CI: 0.017-0.063) and slope of 0.932 (95% CI: 0.839-1.025) compared with 0.080 (95% CI: 0.044-0.117) and 1.419 (95% CI: 1.149-1.690) for the Templeton model. Both models underestimated the live birth rate, but this was particularly marked in the Templeton model. Updating the models to reflect improvements in live birth rates since the models were developed enhanced their performance, but IVFpredict remained superior.

Conclusion: External validation in a large population cohort confirms IVFpredict has superior discrimination and calibration for informing patients, clinicians and healthcare policy makers of the probability of live birth following IVF.

No MeSH data available.