Methods in Human Growth Research

Half-title......Page 2
Series-title......Page 4
Title......Page 6
Copyright......Page 7
Contents......Page 8
Contributors......Page 10
Foreword......Page 12
Acknowledgements......Page 15
Part I Growth data and growth studies: characteristics and methodological issues......Page 16
Introduction......Page 18
Definitions and foci......Page 19
Understanding human biology and physiology......Page 20
Growth charts, references and standards......Page 23
Growth as a bioassay of health and well-being......Page 32
REFERENCES......Page 36
Introduction......Page 42
Basic growth description: a gentle introduction......Page 43
The statistical analysis of growth data......Page 47
Statistical model......Page 50
Use of the velocity in a clinical setting......Page 52
Growth in the First Zürich Longitudinal Study......Page 53
Statistics of the milestones in the First Zürich Longitudinal Study......Page 57
General considerations......Page 59
Distributions in the First Zürich Longitudinal Study......Page 60
Stability of growth......Page 63
Conclusion......Page 65
REFERENCES......Page 66
Sampling schemes......Page 70
Types of samples......Page 71
Implications of type of sampling for analysis......Page 73
Sample size considerations......Page 74
Examples of sampling strategies......Page 77
Indicating morbidity and mortality......Page 78
Assessing and monitoring child health and nutrition......Page 79
REFERENCES......Page 80
Introduction......Page 83
Measuring procedures......Page 87
Stature (stadiometer)......Page 88
Harpenden Stadiometer......Page 91
Sitting height (sitting-height table)......Page 92
Supine or recumbent length (Supine-length/recumbent-length table; neonatometer)......Page 94
Crown–rump length (supine-length/recumbent-length table; neonatometer)......Page 95
Harpenden Neonatometer......Page 96
Calibration......Page 97
Tibial length (anthropometer)......Page 98
Biiliac diameter (anthropometer)......Page 99
Head circumference......Page 101
Arm circumference......Page 102
Waist circumference (abdominal circumference)......Page 103
Skinfolds......Page 104
Triceps skinfold......Page 105
Subscapular skinfold......Page 107
Suprailiac skinfold......Page 108
Lange calliper......Page 110
Weight......Page 111
Acromion process (lateral border of the acromion)......Page 112
Biceps brachii......Page 114
Distal end of the radius......Page 115
Femur epicondyles......Page 116
Gluteal fold......Page 117
Midinguinal point (inguinal crease)......Page 118
Radial styloid......Page 119
Ulna styloid......Page 120
REFERENCES......Page 121
Introduction......Page 123
Initial considerations......Page 124
Methods of assessment......Page 127
Skeletal maturity methods......Page 128
Atlas techniques......Page 130
Bone-specific scoring techniques......Page 131
The Tanner–Whitehouse method......Page 132
The Fels hand–wrist technique......Page 136
Comparability of the atlas and bone-specific methods......Page 137
Population differences......Page 138
Genitalia development......Page 139
Pubic hair development......Page 141
Self-assessment of pubertal status......Page 143
A simplified pubertal questionnaire......Page 145
Age at menarche......Page 146
Secondary sexual events in boys......Page 147
Dental development......Page 148
Landmarks on the growth curve......Page 151
REFERENCES......Page 152
Basic concepts......Page 156
Levels of organization......Page 158
Multicomponent models of body composition......Page 159
Weight-for-height ratios and assessment of obesity......Page 162
Body composition based on anthropometric prediction equations......Page 163
Densitometric methods......Page 166
Hydrodensitometry......Page 167
Air-displacement plethysmography......Page 168
Isotope dilution methods......Page 170
Bioelectrical impedance analysis......Page 172
Total body electrical conductivity......Page 174
Dual-energy X-ray absorptiometry methods......Page 175
In vivo neutron activation analysis......Page 178
Computed tomography......Page 179
Presentation and interpretation of body composition data in children......Page 181
Summary......Page 183
REFERENCE......Page 184
Part II Non-parametric and parametric approaches for individual growth......Page 192
Introduction......Page 194
Modelling longitudinal growth......Page 196
Motivation and de.nition......Page 199
Choice of kernel......Page 201
Choice of bandwidth......Page 202
Application to growth data......Page 205
Shape-invariant modelling......Page 207
Structural analysis......Page 212
Concluding remarks......Page 216
REFERENCES......Page 217
Why model growth data?......Page 220
Non-structural versus structural models......Page 222
Growth in infancy and childhood......Page 224
Logistic and Gompertz functions......Page 227
Preece–Baines model 1 (PB1)......Page 228
The BTT model......Page 232
The Shohoji–Sasaki or Count–Gompertz function......Page 234
The JPA-2 model......Page 236
Biological parameters and structural average curve......Page 237
Assumptions of non-linear regression......Page 241
Independence of residuals......Page 242
Goodness of fit......Page 243
REFERENCES......Page 245
9 Parameter estimation in the context of non-linear longitudinal growth models......Page 249
Maximum likelihood estimation......Page 250
Maximum a posteriori estimation......Page 254
Example 2: Fitting the JPA-2 model......Page 258
Consistent estimation of the population mean and covariance matrix of the model parameters......Page 259
Maximum marginal likelihood estimation of the population means and covariances of the model parameters......Page 264
Allowance for autocorrelated residuals......Page 266
Example 3: Estimation of a common autocorrelation function......Page 270
REFERENCES......Page 271
Part III Methods for population growth......Page 274
Rationale for references......Page 276
Purposes of anthropometry......Page 277
Indices of growth......Page 279
Distance, velocity and conditional references......Page 280
Modes of display......Page 281
Reference populations......Page 282
Study designs......Page 284
Sample size......Page 285
Aims of analytic methods......Page 287
Empirical versus model-based estimation of size......Page 288
Incorporating variation across age for distance references......Page 289
Comparison of methods for constructing distance references......Page 290
Methods for constructing velocity and conditional references......Page 291
2000 CDC Growth Charts......Page 292
Cole et al. (2000) reference for body mass index......Page 293
Construction of growth references......Page 294
Use of growth references......Page 295
REFERENCES......Page 297
Introduction......Page 302
Latent variables......Page 303
Exploratory measurement model: PCA......Page 304
ANTHROPOMETRIC MEASUREMENTS......Page 305
Statistical method......Page 306
Confirmatory measurement models......Page 307
Example of calculation of alpha......Page 308
Structural models......Page 310
Example of a structural model......Page 313
Data requirements......Page 315
Remarks and recommendations......Page 318
REFERENCES......Page 319
Introduction......Page 321
Example data......Page 322
Cross-sectional versus longitudinal data......Page 324
Multilevel data structure......Page 325
Multilevel data layout......Page 326
Multilevel Analysis......Page 328
Development of the multilevel model......Page 330
Curve shaping......Page 333
Fit of the model......Page 334
Modelling strategy......Page 335
Centring data......Page 336
Worked example......Page 337
Final model of the example data......Page 340
Summary......Page 343
REFERENCES......Page 344
Part IV Special topics......Page 346
Introduction......Page 348
Goals of genetic studies of growth......Page 349
Assessing the importance of genes......Page 350
Concept of heritability: definition and utility......Page 351
Familial study designs......Page 352
Twin studies......Page 353
Extended pedigrees......Page 354
Quantitative genetic analysis......Page 355
Multivariate quantitative genetic analysis......Page 356
Genetic correlations of a single trait at different times......Page 357
Genetic correlations between different traits......Page 358
Gene × environment interaction......Page 359
Gene × sex interaction......Page 360
Localizing genes influencing growth-related traits......Page 361
Quantitative trait linkage analysis......Page 362
Variance components linkage analysis......Page 363
Multivariate linkage analysis......Page 364
Summary and conclusion......Page 366
REFERENCES......Page 367
Introduction......Page 369
Predicting adult stature......Page 372
Approaches to prediction......Page 373
Parental size......Page 374
Single predictors......Page 375
Multiple predictors......Page 376
Predicting adult size by determining the percentage of completed growth......Page 377
Multivariate prediction......Page 378
Validation......Page 384
The principles of prediction......Page 385
REFERENCES......Page 386
Introduction......Page 389
Ordinal logit models......Page 391
Three approaches to longitudinal data......Page 397
Marginal models......Page 398
Transitional models......Page 400
Random-effects growth models......Page 401
Combining the three approaches......Page 403
Application to data set on marijuana use......Page 404
Special issues......Page 406
REFERENCES......Page 407
Index......Page 409