Table Of ContentFelix Ladstätter/Eva Garrosa
Prediction of Burnout
An Artificial Neural Network Approach
Diplom.de
Felix Ladstätter/Eva Garrosa
Prediction of Burnout
An Artificial Neural Network Approach
ISBN: 978-3-8366-1141-1
Druck Diplomica® Verlag GmbH, Hamburg, 2008
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Contents
Contents.............................................................................................i
List of Figures..................................................................................iv
List of Tables..................................................................................vii
1 Burnout......................................................................................... 1
1.1 The Origin of Burnout............................................................................1
1.1.1 The Uncovering of Burnout........................................................2
1.2 Burnout as a Global Problem.................................................................3
1.3 Why is Burnout increasing?...................................................................4
1.4 Understanding Burnout..........................................................................7
1.4.1 Definitions..................................................................................8
1.4.2 Possible Symptoms...................................................................10
1.4.3 Burnout vs. Job Stress...............................................................13
1.4.4 Burnout vs. Depression.............................................................14
1.4.5 Burnout vs. Chronic Fatigue.....................................................14
1.5 Assessment and Prevalence..................................................................15
1.5.1 Assessment Tools.....................................................................15
1.5.2 Reliability and Validity.............................................................16
1.5.3 Self-report Measures of Burnout..............................................18
1.5.4 How often does Burnout occur?...............................................21
1.6 Correlates, Causes and Consequences..................................................22
1.6.1 Possible Antecedents of Burnout..............................................24
1.6.2 Possible Consequences of Burnout...........................................28
1.7 Theoretical Approaches to Explain Burnout........................................30
1.7.1 An Integrative Model................................................................31
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1.8 Prevention and Intervention of Burnout...............................................33
1.8.1 Classification............................................................................33
1.8.2 Individual Level Interventions..................................................35
1.8.3 Individual/Organizational Level Interventions.........................38
1.8.4 Organizational Level Interventions..........................................42
2 Artificial Neural Networks..........................................................47
2.1 Introduction to Neurocomputing..........................................................47
2.1.1 Biological Motivation...............................................................48
2.1.2 Evolution of Artificial Neural Networks..................................50
2.1.3 Categorization of Artificial Neural Networks..........................52
2.2 Artificial Neuron Model.......................................................................53
2.2.1 Notation and Terminology.......................................................53
2.2.2 Single-Input Neuron.................................................................54
2.3 Basic Transfer Functions......................................................................55
2.3.1 Hard Limit Transfer Function..................................................56
2.3.2 Linear Transfer Function..........................................................57
2.3.3 Sigmoid Transfer Function.......................................................57
2.3.4 Hyperbolic Tangent Sigmoid Transfer Function......................58
2.3.5 Radial Basis Transfer Function (Gaussian Function)...............59
2.4 Multiple-Input Neuron.........................................................................60
2.5 Training Algorithms.............................................................................61
2.6 Network Architectures.........................................................................63
2.6.1 A Single Layer of Neurons.......................................................63
2.6.2 Multiple Layers of Neurons......................................................64
2.7 Perceptron.............................................................................................66
2.7.1 Perceptron Learning Rule.........................................................68
2.7.2 The Perceptron Training Algorithm.........................................69
2.7.3 Limitations of the Perceptron...................................................70
2.8 Self-Organizing Map (SOM)...............................................................71
2.8.1 Competitive Learning...............................................................72
2.8.2 Kohonen Training Algorithm...................................................78
2.8.3 Example of the Kohonen Algorithm........................................79
2.8.4 Problems with the Kohonen Algorithm....................................80
2.9 Multi-layer Feed-forward Networks....................................................82
2.9.1 Hidden-Neurons.......................................................................84
2.9.2 Back-propagation.....................................................................85
2.9.3 Back-propagation Training Algorithm.....................................91
2.9.4 Problems with Back-propagation.............................................99
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2.10 Radial Basis Function (RBF) Network...............................................107
2.10.1 Functioning of the Radial Basis Network...............................111
2.10.2 The Pseudo Inverse (PI) RBF Training Algorithm.................113
2.10.3 Example of the PI RBF Algorithm.........................................116
2.10.4 The Hybrid RBF Training Algorithm.....................................118
2.10.5 Example of the Hybrid RBF Training Algorithm...................124
2.10.6 Problems with Radial Basis Function Networks....................128
3 Application of ANNs to Burnout Data.....................................130
3.1 Introduction........................................................................................131
3.1.1 The Nursing Profession..........................................................131
3.1.2 Burnout in Nurses...................................................................132
3.1.3 Objective.................................................................................135
3.2 Data....................................................................................................136
3.2.1 Participants.............................................................................136
3.2.2 Measures.................................................................................137
3.2.3 Statistical Data Analysis.........................................................138
3.2.4 Variables used for the Development of the ANNs.................138
3.3 Implementation of the NuBuNet (Nursing Burnout Network)...........139
3.3.1 Self-Organizing Map (SOM)..................................................140
3.3.2 Three-layer Feed-forward Back-propagation Network..........142
3.3.3 Radial Basis Function Network..............................................144
3.4 Processing the Data............................................................................145
3.4.1 Data Preparation (Pre-Processing)..........................................145
3.4.2 Network Preparation and Training.........................................148
3.4.3 Post-Processing.......................................................................152
3.5 Results................................................................................................152
3.5.1 Three-layer Feed-forward Back-propagation Network..........153
3.5.2 Radial Basis Function Network (PI Algorithm).....................168
3.5.3 Radial Basis Function Network (Hybrid Algorithm).............179
3.5.4 Comparison of the Results......................................................197
3.6 Discussion..........................................................................................199
4 References ................................................................................207
4.1 Burnout...............................................................................................207
4.1.1 Internet Directions..................................................................218
4.2 Artificial Neural Networks.................................................................219
4.2.1 Internet Directions..................................................................225
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List of Figures
Figure 1.1 Stress curve (A, B) vs. burnout curve(C, D) (adapted from
Brill (1984)).....................................................................................................13
Figure 1.2 Integrative model of burnout (adapted from Schaufeli and
Enzmann (1998)).............................................................................................32
Figure 1.3 Cognitive behavioral chain............................................................37
Figure 2.1 Illustration of biological neurons (adapted from Hagan et al.,
1996)................................................................................................................49
Figure 2.2 Sum of signals from three neurons.................................................50
Figure 2.3 Single-input neuron........................................................................55
Figure 2.4 Hard limit transfer function............................................................56
Figure 2.5 Linear transfer function..................................................................57
Figure 2.6 Sigmoid transfer function...............................................................58
Figure 2.7 Hyperbolic tangent sigmoid transfer function...............................59
Figure 2.8 Radial basis transfer function.........................................................60
Figure 2.9 Multiple-input neuron....................................................................60
Figure 2.10 A single layer of neurons.............................................................63
Figure 2.11 Three-layer network.....................................................................65
Figure 2.12 Perceptron with N inputs..............................................................67
Figure 2.13 Linear separability in a two-input perceptron..............................68
Figure 2.14 Two-dimensional plots of three logical operations......................70
Figure 2.15 Kohonen SOM (adapted from Negnevitsky (2005))....................73
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Figure 2.16 Kohonen network........................................................................74
Figure 2.17 Euclidean distance between input vector p and weight
vector w..........................................................................................................75
j
Figure 2.18 Mexican hat function...................................................................76
Figure 2.19 Graphical representation of a moving winner neuron.................77
Figure 2.20 Rectangular Neighborhood function...........................................77
Figure 2.21 Multi-layer feed-forward neural network....................................82
Figure 2.22 Input-layer neuron.......................................................................83
Figure 2.23 Output-layer neuron....................................................................84
Figure 2.24 Hidden-layer neuron....................................................................85
Figure 2.25 Weight and bias of neurons.........................................................87
Figure 2.26 Three-layer feed-forward back-propagation network.................92
Figure 2.27 Example 1-2-1 network...............................................................96
Figure 2.28 Two-dimensional example of a local and a global minimum...100
Figure 2.29 Example function used to investigate local and global minima 101
Figure 2.30 Mean squared error surface varying θ1 and w1 ......................102
2 2,1
Figure 2.31 Mean squared error surface varyingw2 and w1 .....................103
1,2 2,1
Figure 2.32 Momentum effect on oscillation...............................................105
Figure 2.33 Radial basis function network...................................................108
Figure 2.34 Radial basis neuron...................................................................109
Figure 3.1 Factors affecting nursing burnout (adapted from Garrosa et al.
(2008))..........................................................................................................139
Figure 3.2 Architecture of the SOM network for the data pre-processing...141
Figure 3.3 Architecture of the three-layer feed-forward network used
for the burnout-model approximation...........................................................143
Figure 3.4 Architecture of the RBF network used for the burnout-model
approximation...............................................................................................144
Figure 3.5 Illustration of the burnout data pre-processing steps..................147
Figure 3.6 MLP training results....................................................................160
Figure 3.7 MLP validation results................................................................161
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Figure 3.8 Linear regression for the emotional exhaustion dim....................162
Figure 3.9 Linear regression for the depersonalization dim..........................162
Figure 3.10 Linear regression for the lack of pers. accomplishment dim.....163
Figure 3.11 Confidence interval for the emotional exhaustion dim..............164
Figure 3.12 Confidence interval for the depersonalization dim....................165
Figure 3.13 Confidence interval for the lack of pers. accomplishment dim.166
Figure 3.14 RBFPINet training results..........................................................171
Figure 3.15 RBFPINet validation results......................................................172
Figure 3.16 Linear regression for the emotional exhaustion dim..................173
Figure 3.17 Linear regression for the depersonalization dim........................174
Figure 3.18 Linear regression for the lack of pers. accomplishment dim.....174
Figure 3.19 Confidence interval for the emotional exhaustion dim..............175
Figure 3.20 Confidence interval for the depersonalization dim....................177
Figure 3.21 Confidence interval for the lack of pers. accomplishment dim.178
Figure 3.22 RBFHNet training results...........................................................189
Figure 3.23 RBFHNet validation results.......................................................190
Figure 3.24 Linear regression for the emotional exhaustion dim..................191
Figure 3.25 Linear regression for the depersonalization dim........................192
Figure 3.26 Linear regression for the lack of pers. accomplishment dim.....192
Figure 3.27 Confidence interval for the emotional exhaustion dim..............193
Figure 3.28 Confidence interval for the depersonalization dim....................194
Figure 3.29 Confidence interval for the lack of pers. accomplishment dim.195
vi
List of Tables
Table 1.1 Possible burnout symptoms at individual level (adapted from
Schaufeli and Enzmann (1998)).....................................................................11
Table 1.2 Normative data of the MBI based on 73 US studies published
between 1979 and 1998 (adapted from Schaufeli and Enzmann (1998)).......22
Table 1.3 Possible causes of burnout (adapted from Schaufeli and
Enzmann (1998))............................................................................................23
Table 1.4 Possible consequences of burnout (adapted from Schaufeli and
Enzmann (1998))............................................................................................28
Table 1.5 Overview of burnout interventions (adapted from Schaufeli and
Enzmann (1998))............................................................................................34
Table 3.1 Specific characteristics of the nursing profession........................133
Table 3.2 Data sets for network training and validation after
pre-processing...............................................................................................148
Table 3.3 MLP parameter for the burnout-model network...........................149
Table 3.4 RBF (PI algorithm) parameter for the burnout-model network...150
Table 3.5 RBF (hybrid algorithm) parameter for the burnout-model
network.........................................................................................................151
Table 3.6 Descriptive statistic of the burnout-model data............................152
Table 3.7 All MLP results for data set 1.......................................................154
Table 3.8 All MLP results for data set 2.......................................................155
Table 3.9 All MLP results for data set 3.......................................................156
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Table 3.10 Means of the MLP results for data set 1......................................157
Table 3.11 Means of the MLP results for data set 2......................................157
Table 3.12 Means of the MLP results for data set 3......................................158
Table 3.13 Means of the MLP results for all data sets..................................158
Table 3.14 Means of the MLP results for all numbers of neurons................159
Table 3.15 Examples for the prediction of the emotional exhaustion dim....164
Table 3.16 Examples for the prediction of the depersonalization dim..........165
Table 3.17 Examples for the prediction of the lack of pers. accompl. dim...167
Table 3.18 Hidden-layer weights...................................................................167
Table 3.19 Hidden-layer biases.....................................................................168
Table 3.20 Output-layer weights...................................................................168
Table 3.21 Output-layer biases......................................................................168
Table 3.22 All RBFPINet results for data set 1.............................................169
Table 3.23 All RBFPINet results for data set 2.............................................170
Table 3.24 All RBFPINet results for data set 3.............................................170
Table 3.25 Examples for the prediction of the emotional exhaustion dim....176
Table 3.26 Examples for the prediction of the depersonalization dim..........177
Table 3.27 Examples for the prediction of the lack of pers. accompl. dim...178
Table 3.28 RBFHNet with σ = 0.54, α = 0.01, β = 0.00001, γ = 0................180
Table 3.29 RBFHNet with σ = 0.54, α = 0.01, β = γ = 0.00001....................180
Table 3.30 RBFHNet with σ = 0.54, α = 0.01, β = γ = 0.00005....................180
Table 3.31 RBFHNet with σ = 0.54, α = 0.01, β = 0, γ = 0.00001................181
Table 3.32 RBFHNet with σ = 0.54, α = 0.02, β = 0.00001, γ = 0................181
Table 3.33 RBFHNet with σ = 0.54, α = 0.02, β = γ = 0.00001....................182
Table 3.34 RBFHNet with σ = 0.54, α = 0.02, β = γ = 0.00005....................182
Table 3.35 RBFHNet with σ = 0.54, α = 0.02, β = 0.00001, γ = 0................182
Table 3.36 RBFHNet means of Table 3.28 to Table 3.35.............................183
Table 3.37 RBFHNet with σ = 1.10, α = 0.01, β = 0.00001, γ = 0................184
Table 3.38 RBFHNet with σ = 1.10, α = 0.01, β = γ = 0.00001...................184
Table 3.39 RBFHNet with σ = 1.10, α = 0.01, β = γ = 0.00005...................185
Table 3.40 RBFHNet with σ = 1.10, α = 0.01, β = 0, γ = 0.00001................185
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