Parental migration, care-giving practices and left-behind children's nutritional health in rural China

342 Pages·2016·4.76 MB·English

by  Nan Zhang

Parental migration, care-giving practices and left-behind children’s
nutritional health in rural China:
A mixed-methods approach

A thesis submitted to The University of Manchester for the degree of
Doctor of Philosophy
in the Faculty of Medical and Human Sciences

2015

Nan Zhang
School of Nursing, Midwifery, and Social Work
Table of Contents
List of Tables .............................................................................................................. 5
List of Figures ............................................................................................................. 7
List of Abbreviations ................................................................................................. 8
Abstract ..................................................................................................................... 11
Declaration ................................................................................................................ 12
Publications from thesis ........................................................................................... 13
Acknowledgement .................................................................................................... 15
Chapter 1 Introduction ............................................................................................ 16
1.1 Rural-urban migration in China ............................................................................. 17
1.2 The importance of nutrition in child development ................................................. 20
1.3 Potential links between migration and child nutrition ........................................... 22
1.4 Conceptual framework on child nutrition .............................................................. 24
1.5 Research aims and outline of thesis ....................................................................... 26
Chapter 2 Literature review ................................................................................... 28
2.1 Migration and left-behind children’s development ................................................ 29
2.1.1 The global context .......................................................................................................... 29
2.1.2 The Chinese context ....................................................................................................... 34
2.2 Search strategy ....................................................................................................... 36
2.2.1 Review strategy .............................................................................................................. 36
2.2.2 Search literature .............................................................................................................. 36
2.2.3 Considerations of quality checking ................................................................................ 37
2.3 Quantitative research review .................................................................................. 38
2.3.1 Cross-sectional evidence ................................................................................................ 38
2.3.2 Limitations of cross-sectional evidence ......................................................................... 39
2.3.3 Longitudinal evidence .................................................................................................... 40
2.3.4 Limitations of longitudinal evidence .............................................................................. 43
2.4 Qualitative research review .................................................................................... 45
2.4.1 Care-giving practices for left-behind children ................................................................ 45
2.4.2 Limitations of previous studies ...................................................................................... 47
2.5 Summary ................................................................................................................ 48
Chapter 3 Methodology ........................................................................................... 58
3.1 Mixed methodology ............................................................................................... 59
3.1.1 Mixed methods ............................................................................................................... 59
3.1.2 Rationale for mixed methods.......................................................................................... 60
3.1.3 Considerations ................................................................................................................ 61
3.2 Quantitative methods ............................................................................................. 66
3.2.1 Study aims, objectives, and hypotheses .......................................................................... 66
3.2.2 Data sources ................................................................................................................... 66
3.2.3 Target population and attrition ....................................................................................... 68
3.2.4 Nutritional outcomes ...................................................................................................... 70
3.2.5 Exposures and covariates ............................................................................................... 73
3.2.5 Statistical analysis .......................................................................................................... 77
3.3 Qualitative methods ............................................................................................... 81
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3.3.1 Rationale for the qualitative study design ...................................................................... 81
3.3.2 Research site ................................................................................................................... 81
3.3.3 Sampling and recruitment .............................................................................................. 86
3.3.4 Ethical concerns ............................................................................................................. 91
3.3.5 Data collection ................................................................................................................ 93
3.3.6 Data analysis .................................................................................................................. 95
3.3.7 Rigour and reflexivity .................................................................................................... 96
Chapter 4 Patterns and distributions of under-and over-nutrition among rural
children: Evidence from rural China ................................................................... 102
4.1 Introduction .......................................................................................................... 103
4.2 Methods................................................................................................................ 106
4.2.1 Study design and subjects ............................................................................................. 106
4.2.2 Nutritional outcomes .................................................................................................... 107
4.2.3 Variables....................................................................................................................... 110
4.3 Results .................................................................................................................. 111
4.4 Conclusions .......................................................................................................... 112
Chapter 5 Does the timing of parental migration matter for child growth? A life
course study on left-behind children in rural China .......................................... 119
5.1 Abstract ................................................................................................................ 121
5.2 Background .......................................................................................................... 122
5.3 Methods................................................................................................................ 123
5.3.1 Data .............................................................................................................................. 123
5.3.2 Target population ......................................................................................................... 124
5.3.3 Variables....................................................................................................................... 124
5.3.4 Analysis ........................................................................................................................ 125
5.4 Results .................................................................................................................. 128
5.5 Discussion ............................................................................................................ 130
5.6 Conclusion ........................................................................................................... 134
Chapter 6 Gender differences in parental migration and left-behind children’s
macronutrient intakes in rural China: A multilevel analysis ............................ 143
6.1 Abstract ................................................................................................................ 145
6.2 Introduction .......................................................................................................... 146
6.3 Methods................................................................................................................ 148
6.3.1 Study design and subjects ............................................................................................. 148
6.3.2 Dietary variables and covariates ................................................................................... 149
6.3.3 Statistical analysis ........................................................................................................ 151
6.4 Results .................................................................................................................. 154
6.5 Discussion ............................................................................................................ 157
Chapter 7 Intergenerational obligations for children left behind by parental
migration in rural China ....................................................................................... 172
7.1 Abstract ................................................................................................................ 174
7.2 Introduction .......................................................................................................... 175
7.3 Methodology and data .......................................................................................... 178
7.3.1 Research setting ............................................................................................................ 179
7.3.2 Data collection .............................................................................................................. 179
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7.3.3 Data analysis ................................................................................................................ 180
7.4 Results .................................................................................................................. 181
7.4.1 Migration to ‘make ends meet’ ..................................................................................... 181
7.4.2 Migration to meet social obligations for sons............................................................... 184
7.4.3 Taking on care-giving roles for left-behind children .................................................... 187
7.5 Conclusion ........................................................................................................... 195
Chapter 8 Intergenerational differences in beliefs about healthy eating among
carers of left-behind children in rural China: A qualitative study ................... 201
8.1 Abstract ................................................................................................................ 203
8.2 Introduction .......................................................................................................... 204
8.3 Methods................................................................................................................ 206
8.3.1 Setting .......................................................................................................................... 206
8.3.2 Ethics ............................................................................................................................ 206
8.3.3 Data collection .............................................................................................................. 207
8.3.4 Data analysis ................................................................................................................ 208
8.4 Results .................................................................................................................. 209
8.4.1 Socio-demographic characteristics ............................................................................... 209
8.4.2 Intergenerational differences in healthy eating beliefs ................................................. 209
8.5 Discussion ............................................................................................................ 217
Chapter 9 Discussion and conclusion ................................................................... 223
9.1 Summary of results .............................................................................................. 224
9.2 Contributions ........................................................................................................ 230
9.3 Limitations ........................................................................................................... 231
9.3.1 Measurements ............................................................................................................... 231
9.3.2 Longitudinal cohorts study design ................................................................................ 232
9.3.3 Missing data/attrition .................................................................................................... 233
9.3.4 Association or causation ............................................................................................... 235
9.3.5 Reflexive consideration of the qualitative research ...................................................... 238
9.4 Recommendations ................................................................................................ 239
9.5 Final conclusion ................................................................................................... 242
References ............................................................................................................... 243
Appendices .............................................................................................................. 267

Word count: approximately 72,000
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List of Tables

Table 2-1 Quantitative studies examining the associations between parental
migration and children’s nutritional health in rural China (N=8) ....................... 50
Table 2-2 Studies on care-giving practices for left-behind children in rural China
(N=5) ................................................................................................................... 55
Table 3-1 Sample size and characteristics of left-behind children and non-left-behind
children (N=26) .................................................................................................. 99
Table 3-2 Sample size and characteristics of caregivers (N=32) ............................. 100
Table 4-1 Participation of rural children aged 0-17 years across survey waves from
the CHNS, 1997 to 2009 ................................................................................... 107
Table 4-2 Six scenarios of childhood malnutrition status ........................................ 108
Table 4-3 Sample size and percentage of stunting across overweight/underweight
status from the CHNS, 1997-2009 .................................................................... 109
Table 4-4 Sample size and percentage of malnutrition status in four categories for the
CHNS children (1997-2009) in rural China ..................................................... 110
Table 4-5 Sample size and distribution of rural children under 6 years across stunting,
underweight and overweight from the CHNS, 1997-2009 ............................... 113
Table 4-6 Sample size and distribution of rural children aged 6-17 across stunting,
underweight and overweight from the CHNS, 1997-2009 ............................... 114
Table 4-7 Sample size and distribution of rural children aged under 6 years across
malnutrition in six scenarios from the CHNS, 1997-2009 ............................... 115
Table 4-8 Sample size and distribution of rural children aged 6-17 years across
malnutrition in six scenarios from the CHNS, 1997-2009 ............................... 116
Table 4-9 Sample size and distribution of rural children aged under 6 years across
malnutrition in four scenarios from the CHNS, 1997-2009 ............................. 117
Table 4-10 Sample size and distribution of rural children aged 6-17 years across
malnutrition in four scenarios from the CHNS, 1997-2009 ............................. 118
Table 5-1 Characteristics and health outcomes of children aged 0-17 by gender in
rural China from the CHNS, 1997-2009 ........................................................... 136
Table 5-2 Estimates (standard errors) of height and growth curve models fitted to
boys and girls in rural China from the CHNS, 1997-2009 ............................... 137
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Table 5-3 Estimates (standard errors) of weight and growth curve models fitted to
boys and girls in rural China from the CHNS, 1997-2009 ............................... 138
Table 6-1 Means (standard deviations) of macronutrient intakes and relative
macronutrient intakes (%) of boys and girls by left-behind patterns in rural
China from the CHNS, 1997-2009 ................................................................... 163
Table 6-2 Estimates (standard errors) of relative protein intake (%) from multilevel
modelling fitted to rural children across gender and age groups from the CHNS,
1997-2009 ......................................................................................................... 164
Table 6-3 Estimates (standard errors) of relative fat intake (%) from multilevel
modelling fitted to rural children across gender and age groups from the CHNS,
1997-2009 ......................................................................................................... 165
Table 6-4 Estimates (standard errors) of relative carbohydrate intake (%) from
multilevel modelling fitted to rural children across gender and age groups from
the CHNS, 1997-2009....................................................................................... 166
Table 6-5 Selected parameter estimates (standard errors) from a multinomial logit
model [using within AMDR as the reference] for two scenarios of relative fat
intake (%) including under AMDR lower limit, over AMDR upper limit for
boys and girls aged 1-17 year in rural China, with adjustment for clustering at
individual and village levels ............................................................................. 169
Table 6-6 Selected parameter estimates (standard errors) from a multinomial logit
model [using within AMDR as the reference] for two scenarios of relative
carbohydrate intake (%) including under AMDR lower limit, over AMDR upper
limit for boys and girls aged 1-17 years in rural China, with adjustment for
clustering at individual and village levels ......................................................... 170
Table 6-7 Estimates (Standard errors) of relative protein (%) and fat (%) intakes
from multilevel modelling based on imputed dataset (n=30) for rural children
from the CHNS, 1997-2009 .............................................................................. 171
Table 7-1 Sample size and characteristics of left-behind children (N=21) .............. 198
Table 7-2 Sample size and characteristics of left-behind children's caregivers (N=28)
.......................................................................................................................... 199
Table 7-3 Remittances from migrant parent(s) to non-parental caregivers (N=16) 200
Table 7-4 Remittances distribution for non-parental caregivers who received
remittances ........................................................................................................ 200
Table 8-1 Caregivers' beliefs about health eating for children (N=32) .................... 221
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Table 8-2 Food items from children's diaries (N=24) .............................................. 222
List of Figures
Figure 1-1 Conceptual framework for left-behind children's nutrition (modified from
UNICEF framework) .......................................................................................... 27
Figure 3-1 The care triangle ....................................................................................... 65
Figure 3-2 The simplified theoretical framework ...................................................... 65
Figure 3-3 China map and the CHNS survey provinces ............................................ 68
Figure 3-4 The flowchart depicting selection of participants in the CHNS from 1997
to 2009 (N=7833) ............................................................................................... 69
Figure 3-5 Multilevel structure of the CHNS children .............................................. 78
Figure 3-6 A picture of a participant's vegetable garden in the backyard .................. 83
Figure 3-7 A picture of a village road to a participant's home ................................... 84
Figure 3-8 A picture of school lunch including steamed rice on the bottom, stir-fried
mixed vegetables and sweet potato vermicelli on the top .................................. 86
Figure 3-9 Summary of main themes from integrated analysis ............................... 101
Figure 5-1 Trajectories of height for boys in rural China (estimated from model 2,
Table 5.2) .......................................................................................................... 139
Figure 5-2 Trajectories of height for girls in rural China (estimated from model 2,
Table 5.2) .......................................................................................................... 140
Figure 5-3 Trajectories of weight for boys in rural China (estimated from model 2,
Table 5.3) .......................................................................................................... 141
Figure 5-4 Trajectories of weight for girls in rural China (estimated from model 2,
Table 5.3) .......................................................................................................... 142
Figure 6-1 Missing data in multilevel modelling on relative macronutrient intakes of
rural children from the CHNS, 1997-2009 ....................................................... 153
Figure 6-2 Relative macronutrient intakes including (A) protein, (B) fat and (C)
carbohydrate of preschool and school boys and girls by left-behind patterns in
rural China from CHNS, 1997-2009................................................................. 167
Figure 6-3 Prevalence of rural children with relative macronutrient intakes within,
below, and over AMDR ranges for (a) protein, (b) fat, and (c) carbohydrate for
boys and girls in rural China from the CHNS, 1997-2009 ............................... 168
Figure 9-1 Integration of quantitative and qualitative findings ............................... 229
Figure 9-2 Urbanization rates in China, 1993-2011................................................. 235
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List of Abbreviations

LBC: left-behind children
Non-LBC: non-left-behind children
CHNS: China Health and Nutrition Survey
HAZ: height-for-age Z-scores
WAZ: weight-for-age Z-scores
BMIZ: body-mass-index Z-scores
WHZ: weight-for-height Z-scores
UNICEF: United Nations Children’s Fund
LBW: low-birth weight
SDQ: Strengths and Difficulties Questionnaire
HRQoL: health-related quality of life
CASP: Critical Appraisal Skills Programme
PSM: propensity score matching
IV: instrumental variables
GCM: Growth Curve Model
MCAR: Missing Complete At Random
MAR: Missing At Random
MNAR: Missing Not At Random
MI: Multiple imputation
IOTF: International Obesity Task Force
WHO: World Health Organization
LMS: Lambda-Mu-Sigma
NCHS: National Centre for Health Statistics
MGRS: Multicentre Growth Reference Study
DRI: Dietary reference intakes
FCT: Food Composition Table
OR: odds ratios
CI: confidence intervals
OLS: ordinary least squares
AMDR: Acceptable Macronutrient Distribution Ranges
MICE: Multiple Imputation using Chained Equations
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SD: standard deviations
SE: standard errors
NCMS: New Cooperative Medical Scheme
NBSC: National Bureau of Statistics of China
RMB: Renminbi (the official currency of People’s Republic of China)
GBP: Pound Sterling
USD: The United States Dollar

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Appendices
Appendix 1 Topic guide for carers........................................................................... 268
Appendix 2 Chinese version for topic guide for carers............................................ 269
Appendix 3 Topic guide for left-behind children .................................................... 270
Appendix 4 Chinese version for topic guide for left-behind children ..................... 271
Appendix 5 Topic guide for non-left-behind children ............................................. 272
Appendix 6 Chinese version for topic guide for non-left-behind children .............. 273
Appendix 7 Diary booklet format for children ........................................................ 274
Appendix 8 Chinese version for diary booklet format for children ......................... 276
Appendix 9 Carers’ information sheet ..................................................................... 278
Appendix 10 Chinese version for carers’ information sheet .................................... 283
Appendix 11 Children’s information sheet (aged 6-9) ............................................ 286
Appendix 12 Chinese version for children’s information sheet (aged 6-9) ............. 289
Appendix 13 Children’s information sheet (aged 10-12) ........................................ 292
Appendix 14 Chinese version for children’s information sheet (aged 10-12) ......... 296
Appendix 15 Carers’ consent form .......................................................................... 299
Appendix 16 Chinese version for carers’ consent form ........................................... 302
Appendix 17 Left-behind children’s consent form .................................................. 305
Appendix 18 Chinese version for left-behind children’s consent form ................... 311
Appendix 19 Non-left-behind children’s consent form ........................................... 317
Appendix 20 Chinese version for non-left-behind children’s consent form ............ 323
Appendix 21 Transcriber/Translator confidentiality agreement .............................. 329
Appendix 22 Approval from local government, China ............................................ 331
Appendix 23 Ethics approval from University of Manchester ................................ 334
Appendix 24 School agreement, China .................................................................... 336
Appendix 25 Examples of children’s diary .............................................................. 339
Appendix 26 Question from the CHNS household questionnaire to identify
migration .................................................................................................................. 341
Appendix 27 An example of coding strategy ........................................................... 342

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