Abstract
The development of physical functioning after a caesura in an aged population is still widely unexplored. Analysis of this topic would need to model the longitudinal trajectories of physical functioning and simultaneously take terminal events (deaths) into account. Separate analysis of both results in biased estimates, since it neglects the inherent connection between the two outcomes. Thus, this type of data generating process is best modelled jointly. To facilitate this several software applications were made available. They differ in model formulation, estimation technique (likelihood-based, Bayesian inference, statistical boosting) and a comparison of the different approaches is necessary to identify their capabilities and limitations. Therefore, we compared the performance of the packages JM, joineRML, JMbayes and JMboost of the R software environment with respect to estimation accuracy, variable selection properties and prediction precision. With these findings we then illustrate the topic of physical functioning after a caesura with data from the German ageing survey (DEAS). The results suggest that in smaller data sets and theory driven modelling likelihood-based methods (expectation maximation, JM, joineRML) or Bayesian inference (JMbayes) are preferable, whereas statistical boosting (JMboost) is a better choice with high-dimensional data and data exploration settings.
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Note: Anja Rappl performed the present work in partial fulfilment of the requirements for obtaining the degree ‘Dr. rer. biol. hum.’ at Friedrich-Alexander-Universität Erlangen-Nürnberg.
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Author contribution: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.
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Research funding: The work on this article was supported by the DFG (Projekt WA 4249/2-1) and the Volkswagen Foundation.
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Conflict of interest statement: The authors declare no conflicts of interest regarding this article.
Calculation of MSE
Average MSE-values by model and software.
| Model | Parameter | JM | joineRML | JMbayes | JMboost |
|---|---|---|---|---|---|
| AM1 | β l0 | 0.026 | 0.028 | 0.029 | 0.039 |
| β ls1 | 0.026 | 0.025 | 0.024 | 0.031 | |
| β ls2 | 0.019 | 0.018 | 0.020 | 0.028 | |
| β ls3 | 0.026 | 0.028 | 0.026 | 0.037 | |
| β ls4 | 0.017 | 0.018 | 0.018 | 0.024 | |
| β ls5 | 0.027 | 0.026 | 0.025 | 0.029 | |
| β ls6 | 0.025 | 0.028 | 0.030 | 0.037 | |
| β ls7 | 0.027 | 0.028 | 0.028 | 0.035 | |
| β ls8 | 0.028 | 0.028 | 0.026 | 0.037 | |
| β ls9 | 0.019 | 0.019 | 0.020 | 0.023 | |
| β ls10 | 0.021 | 0.022 | 0.023 | 0.029 | |
| β t | 0.016 | 0.016 | 0.017 | 0.130 | |
| β s | 0.038 | 0.042 | 0.042 | 0.038 | |
| α | 0.007 | 0.031 | 0.007 | 0.011 | |
| σ 2 | 0.040 | 0.002 | 0.035 | 1.019 | |
| B 00 | 0.169 | 0.164 | 0.141 | ||
| B 01/10 | 0.028 | 0.028 | 0.084 | ||
| B 11 | 0.029 | 0.028 | 337.920 | ||
| AM2 | β l0 | 0.026 | 0.026 | 0.056 | 0.044 |
| β l1 | 0.002 | 0.002 | 0.002 | 0.135 | |
| β l2 | 0.002 | 0.002 | 0.002 | 0.132 | |
| β l3 | 0.002 | 0.002 | 0.002 | 0.131 | |
| β l4 | 0.002 | 0.002 | 0.002 | 0.082 | |
| β l5 | 0.001 | 0.001 | 0.001 | 0.137 | |
| β l6 | 0.001 | 0.001 | 0.001 | 0.121 | |
| β t | 0.021 | 0.021 | 0.019 | 0 | |
| β s | 0.048 | 0.050 | 0.052 | 0.033 | |
| α | 0.013 | 0.029 | 0.014 | Inf | |
| σ 2 | 0.039 | 0.002 | 0.036 | 1.444 | |
| B 00 | 0.115 | 0.113 | 0.097 | ||
| B 01/10 | 0.042 | 0.041 | 0.099 | ||
| B 11 | 0.034 | 0.033 | 126.073 | ||
| AM3 | β l0 | 0.028 | 0.028 | 0.032 | 0.040 |
| β l1 | 0.002 | 0.002 | 0.002 | 0.150 | |
| β l2 | 0.002 | 0.002 | 0.002 | 0.144 | |
| β l3 | 0.002 | 0.002 | 0.002 | 0.141 | |
| β l4 | 0.002 | 0.002 | 0.002 | 0.082 | |
| β l5 | 0.001 | 0.001 | 0.001 | 0.149 | |
| β ls1 | 0.022 | 0.022 | 0.238 | 0.031 | |
| β ls2 | 0.024 | 0.023 | 0.037 | 0.029 | |
| β ls3 | 0.023 | 0.023 | 0.296 | 0.030 | |
| β ls4 | 0.023 | 0.022 | 0.020 | 0.024 | |
| β ls5 | 0.027 | 0.026 | 0.051 | 0.030 | |
| β t | 0.021 | 0.022 | 0.032 | 0.160 | |
| β s | 0.044 | 0.044 | 0.047 | 0.040 | |
| α | 0.008 | 0.026 | 0.008 | 0.022 | |
| σ 2 | 0.039 | 0.002 | 0.037 | 1.298 | |
| B 00 | 0.125 | 0.128 | 0.093 | ||
| B 01/10 | 0.041 | 0.040 | 0.113 | ||
| B 11 | 0.035 | 0.034 | 620.771 |
See Table 5.
Median of false-positive and -negative rates of packages by model and dimensionality.
| Model | Software | No. of available simulations | No. of failures | Median false-positive rate [min; max] | Median false-negative rate [min; max] |
|---|---|---|---|---|---|
| V1M1 | JM | 96 | 4 | 0.846 [0.538; 0.923] | 0.000 [0.000; 1.000] |
| joineRML | 100 | 0 | 0.923 [0.692; 0.923] | 0.000 [0.000; 0.500] | |
| JMbayes | 88 | 12 | 0.923 [0.692; 0.923] | 0.000 [0.000; 0.500] | |
| JMboost | 100 | 0 | 0.538 [0.231; 0.769] | 0.188 [0.062; 0.375] | |
| V1M2 | JM | 98 | 2 | 0.923 [0.538; 0.923] | 0.000 [0.000; 1.000] |
| joineRML | 99 | 1 | 0.923 [0.769; 0.923] | 0.000 [0.000; 0.500] | |
| JMbayes | 83 | 17 | 0.923 [0.692; 0.923] | 0.000 [0.000; 1.000] | |
| JMboost | 100 | 0 | 0.385 [0.077; 0.538] | 0.375 [0.167; 0.583] | |
| V1M3 | JM | 95 | 5 | 0.923 [0.615; 0.923] | 0.000 [0.000; 1.000] |
| joineRML | 100 | 0 | 0.923 [0.615; 0.923] | 0.000 [0.000; 0.500] | |
| JMbayes | 77 | 23 | 0.923 [0.769; 0.923] | 0.000 [0.000; 1.000] | |
| JMboost | 97 | 3 | 0.462 [0.154; 0.692] | 0.312 [0.125; 0.562] | |
| V2M1 | JM | 2 | 98 | 0.764 [0.750; 0.777] | 0.250 [0.000; 0.500] |
| joineRML | 2 | 98 | 0.659 [0.635; 0.682] | 0.500 [0.500; 0.500] | |
| JMbayes | 0 | 100 | |||
| JMboost | 100 | 0 | 0.128 [0.061; 0.223] | 0.438 [0.188; 0.625] | |
| V2M2 | JM | 10 | 90 | 0.818 [0.730; 0.912] | 0.000 [0.000; 0.500] |
| joineRML | 1 | 99 | 0.676 [0.676; 0.676] | 0.500 [0.500; 0.500] | |
| JMbayes | 0 | 100 | |||
| JMboost | 100 | 0 | 0.068 [0.041; 0.270] | 0.500 [0.250; 0.667] | |
| V2M3 | JM | 12 | 88 | 0.780 [0.676; 0.865] | 0.000 [0.000; 1.000] |
| joineRML | 1 | 99 | 0.649 [0.649; 0.649] | 0.500 [0.500; 0.500] | |
| JMbayes | 0 | 100 | |||
| JMboost | 100 | 0 | 0.088 [0.027; 0.331] | 0.438 [0.250; 0.688] | |
| V3M1 | JM | 0 | 100 | ||
| joineRML | 0 | 100 | |||
| JMbayes | 0 | 100 | |||
| JMboost | 100 | 0 | 0.028 [0.013; 0.056] | 0.562 [0.250; 0.875] | |
| V3M2 | JM | 0 | 100 | ||
| joineRML | 0 | 100 | |||
| JMbayes | 0 | 100 | |||
| JMboost | 100 | 0 | 0.020 [0.011; 0.057] | 0.500 [0.333; 0.667] | |
| V3M3 | JM | 0 | 100 | ||
| joineRML | 0 | 100 | |||
| JMbayes | 0 | 100 | |||
| JMboost | 100 | 0 | 0.019 [0.007; 0.123] | 0.562 [0.375; 0.750] |
Calculation of MSPE for longitudinal outcomes
Calculation of MSPE for survival outcomes
MSPE-values for marginal prediction of longitudinal outcome by model, dimensionality and package.
| Dimension | Model | JM | joineRML | JMbayes | JMboost |
|---|---|---|---|---|---|
| PA | M1 | 2.76 [2.47; 3.12] | 2.77 [2.46; 3.32] | 2.77 [2.47; 3.23] | 2.82 [2.49; 3.44] |
| PA | M2 | 2.53 [2.30; 2.83] | 2.53 [2.30; 2.83] | 2.54 [2.35; 3.02] | 3.22 [2.83; 3.83] |
| PA | M3 | 2.63 [2.39; 3.19] | 2.63 [2.40; 3.18] | 3.21 [2.44; 4.04] | 3.30 [2.96; 4.04] |
| PV1 | M1 | 2.94 [2.56; 3.43] | 2.95 [2.56; 3.46] | 2.82 [2.50; 3.37] | 2.99 [2.51; 3.59] |
| PV1 | M2 | 2.63 [2.34; 3.07] | 2.64 [2.35; 3.08] | 2.57 [2.36; 3.18] | 3.25 [2.87; 3.83] |
| PV1 | M3 | 2.76 [2.47; 3.21] | 2.77 [2.47; 3.22] | 3.29 [2.66; 3.91] | 3.44 [2.99; 4.14] |
| PV2 | M1 | 6.28 [5.67; 6.89] | 6.65 [6.03; 7.27] | 3.54 [2.79; 4.74] | |
| PV2 | M2 | 4.70 [4.00; 6.24] | 4.64 [4.64; 4.64] | 3.21 [2.86; 3.83] | |
| PV2 | M3 | 5.40 [4.40; 6.24] | 5.89 [5.89; 5.89] | 3.71 [3.18; 5.83] | |
| PV3 | M1 | 4.17 [3.29; 7.35] | |||
| PV3 | M2 | 3.23 [2.87; 3.80] | |||
| PV3 | M3 | 4.14 [3.32; 6.23] |
MSPE-values for subject-specific prediction of the survival probability by model, dimensionality and package.
| Dimension | Model | JM | joineRML | JMbayes | JMboost |
|---|---|---|---|---|---|
| PA | M1 | 0.12 [0.08; 0.19] | 0.24 [0.12; 0.44] | 0.11 [0.08; 0.14] | 0.14 [0.11; 0.16] |
| PA | M2 | 0.13 [0.09; 0.20] | 0.23 [0.13; 0.42] | 0.11 [0.09; 0.14] | |
| PA | M3 | 0.13 [0.10; 0.21] | 0.24 [0.12; 0.43] | 0.11 [0.09; 0.14] | 0.14 [0.11; 0.17] |
| PV1 | M1 | 0.13 [0.08; 0.20] | 0.24 [0.12; 0.44] | 0.11 [0.09; 0.14] | 0.14 [0.11; 0.17] |
| PV1 | M2 | 0.13 [0.09; 0.20] | 0.23 [0.13; 0.42] | 0.11 [0.09; 0.14] | 0.14 [0.11; 0.17] |
| PV1 | M3 | 0.13 [0.10; 0.22] | 0.24 [0.12; 0.43] | 0.11 [0.09; 0.14] | 0.14 [0.11; 0.17] |
| PV2 | M1 | 0.13 [0.13; 0.13] | 0.31 [0.30; 0.33] | 0.14 [0.11; 0.17] | |
| PV2 | M2 | 0.14 [0.12; 0.15] | 0.14 [0.14; 0.14] | 0.14 [0.11; 0.17] | |
| PV2 | M3 | 0.12 [0.11; 0.16] | 0.16 [0.16; 0.16] | 0.14 [0.12; 0.17] | |
| PV3 | M1 | 0.14 [0.11; 0.17] | |||
| PV3 | M2 | 0.14 [0.11; 0.17] | |||
| PV3 | M3 | 0.14 [0.11; 101293.98] |
The update mechanism of statistical boosting algorithms yield characteristic coefficient paths across their set iteration times. They reflect that per iteration only one coefficient per gradient is updated by a small proportion, that coefficients are selected at different times throughout the algorithm and that earlier selected coefficients tend to be larger once the algorithm stops. An example of a standard image of coefficient paths is given in Figure 9.

Ideal behaviour of coefficient paths in statistical boosting.
In comparison Figure 10 shows the coefficient paths of the data example of “healthy ageing”. The paths oscillate heavily, which is a sign of instability. This becomes particularly problematic with the effect of obstime, since it alternates between positive and negative values. The values for mstop_l, mstop_ls and mstop_s indicate the optimal iteration number for the predicted likelihood to be at its minimum (cross-validation). A potential remedy for this behaviour is for the algorithm to be forced to run longer at the compromise of less optimal prediction. In this case, however, the oscillation will not stop even when the iteration numbers are increased. Thus, boosting will not yield entirely satisfying results for this data problem.

Suboptimal trajectory of coefficient paths of the data model “healthy ageing” when boosted.
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Supplementary Material
The online version of this article offers supplementary material (https://doi.org/10.1515/ijb-2020-0067).
© 2021 Walter de Gruyter GmbH, Berlin/Boston
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Articles in the same Issue
- Frontmatter
- Research Articles
- Integrating additional knowledge into the estimation of graphical models
- Asymptotic properties of the two one-sided t-tests – new insights and the Schuirmann-constant
- Bayesian optimization design for finding a maximum tolerated dose combination in phase I clinical trials
- A Bayesian mixture model for changepoint estimation using ordinal predictors
- Power prior for borrowing the real-world data in bioequivalence test with a parallel design
- Bayesian approaches to variable selection: a comparative study from practical perspectives
- Bayesian adaptive design of early-phase clinical trials for precision medicine based on cancer biomarkers
- More than one way: exploring the capabilities of different estimation approaches to joint models for longitudinal and time-to-event outcomes
- Designing efficient randomized trials: power and sample size calculation when using semiparametric efficient estimators
- Power formulas for mixed effects models with random slope and intercept comparing rate of change across groups
- The effect of data aggregation on dispersion estimates in count data models
- A zero-inflated non-negative matrix factorization for the deconvolution of mixed signals of biological data
- Multiple scaled symmetric distributions in allometric studies
- Estimation of semi-Markov multi-state models: a comparison of the sojourn times and transition intensities approaches
- Regularized bidimensional estimation of the hazard rate
- The effect of random-effects misspecification on classification accuracy
- The area under the generalized receiver-operating characteristic curve