Harmonisation of mental health measures in British birth cohorts

George B. Ploubidis

Acknowledgements• CLS

─ George B. Ploubidis, PI─ Alissa Goodman, Co-I─ Praveetha Patalay, Co-I─ Eoin McElroy, Research

Associate─ Aase Villadsen, Research

Associate─ Dawid Gondek, PhD Student

• MRC LHA─ Marcus Richards, Co-I

• ALSPAC ─ Kate Northstone, Advisor

• UCL Clinical, Educational & Health Psychology─ Pasco Fearon, Advisor─ Marc Tibber, Advisor

Acknowledgements

The work described in this presentation was funded by CLOSER, the home of longitudinal research. CLOSER is funded by the ESRC grant reference: ES/K000357/1. www.closer.ac.uk

http://www.closer.ac.uk/

Outline

• Harmonisation process

• Measurement properties

• Outputs

• Barriers to comparability─Content─ Scale─Reporter

Harmonisation

• Content─Old School, 3 psychologists ─Which items tap into the same symptom?─ Interrater reliability

Harmonisation

Harmonisation

General Health Questionnaire (28-item) (GHQ-28) Malaise Inventory (9 item)

Tense

Rater 1 16. Felt constantly under strain7. Are you constantly keyed up and jittery?

Rater 2 16. Felt constantly under strain7. Are you constantly keyed up and jittery?

AgreementIrritability

Rater 118. Been getting edgy and bad-temptered (possibly…)

6. Are you easily upset or irritated? (somewhat weak item)

Rater 218. Been getting edgy and bad-temptered

6. Are you easily upset or irritated?

AgreementLow Mood

Rater 117. Been able to enjoy your normal day-to-day activities

2. Do you often feel miserable or depressed?

Rater 23. Been feeling run down and out of sorts

2. Do you often feel miserable or depressed?

Agreement

Harmonisation

GHQ

(28-ite

m)

GHQ

(12-ite

m)

PSFS

(18 i

tems)

Prese

nt Sta

te

Exam

inatio

n

Malai

se In

vento

ry (9

item)

Malai

se In

vento

ry (24

items

)

SF-36

CES-D

Kessl

er sca

le (4

items

)

Low MoodFatigue

Tense/stressedSleep problems

WorryGeneral anxiety

IrritabilityPanic

HopelessnessLoss of interest

Concentration problemsImpairment/functionality

Appetite disturbance Health Anxiety/perceived poor health

Restlessness Social phobia

Cognitive impairment - IndecisionSomatic complaints

Wothlessness/self-esteemMotivation

Suicidal ideation

Measurement properties: Aims• Explore and document measurement properties of

scales in original format• Examine comparability of scales administered in

different sweeps/cohorts • Explore and document measurement properties of

harmonised scales• Examine comparability of harmonised scales

Measurement properties

• Identical items/scales within and between cohorts Do cohort members interpret mental health questions in the same

way as they age?

Are there generational differences in the interpretation of items? Are there within (age) and/or between (generational change)

differences in reliability/precision?

• Harmonised items within and between cohorts As above How do the harmonised items compare to the overall scales? Are

they capturing a similar construct?

Measurement properties

Low mood Tension

Distress NSHD

λ

Fatigue PanicLow

mood Tension

Distress NCDS

Fatigue PanicLow

mood Tension

Distress BCS

Fatigue Panic

λ λ λ λ λ λ λ λ λλ λ

1τ τ τ τ

1τ τ τ τ

1τ τ τ τ

Measurement

Low mood Tension

Distress NSHD

λ

Fatigue PanicLow

mood Tension

Distress NCDS

Fatigue PanicLow

mood Tension

Distress BCS

Fatigue Panic

λ λ λ λ λ λ λ λ λλ λ

1τ τ τ τ

1τ τ τ τ

1τ τ τ τ

Measurement

Low mood Tension

Distress NSHD

λ

Fatigue PanicLow

mood Tension

Distress NCDS

Fatigue PanicLow

mood Tension

Distress BCS

Fatigue Panic

λ λ λ λ λ λ λ λ λλ λ

1τ τ τ τ

1τ τ τ τ

1τ τ τ τ

Reliability/precision: Scale Information Function

Fisher information

Level of the latent trait (SD)

0

2

4

6

8

10

12

14

-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6

BCS Age 30 Malaise Inventory (24-item Version)

Results – Comparisons across waves and cohorts

NCDS BCS

Age 23 Malaise Inventory (24 items)

Age 26 Malaise Inventory (24 items)

Age 30 Malaise Inventory (24 items)

Age 33 Malaise Inventory (24 items)Age 34 Malaise (9 items)

Age 42 Malaise Inventory (24 items) Malaise (9 items)

Age 46 Malaise (9 items)

Age 50 Malaise Inventory (9 item)

Results – Comparisons across waves and cohorts

Low moo

d

Tension

Psychological

Distress

λ1

Fatigue

Panic

λ2 λ3 λ4

τ1 τ2 τ3 τ4

ε1

ε2

ε3

ε4

1*

0

Low moo

d

Tension

Psychological

Distress

λ1

Fatigue

Panic

λ2 λ3 λ4

τ1 τ2 τ3 τ4

ε1

ε2

ε3

ε4

1*

0

Low moo

d

Tension

Psychological

Distress

λ1

Fatigue

Panic

λ2 λ3 λ4

τ1 τ2 τ3 τ4

ε1

ε2

ε3

ε4

1*

0

Low moo

d

Tension

Psychological

Distress

λ1

Fatigue

Panic

λ2 λ3 λ4

τ1 τ2 τ3 τ4

ε1

ε2

ε3

ε4

1*

0

Low moo

d

Tension

Psychological

Distress

λ1

Fatigue

Panic

λ2 λ3 λ4

τ1 τ2 τ3 τ4

ε1

ε2

ε3

ε4

1*

0

Low moo

d

Tension

Psychological

Distress

λ1

Fatigue

Panic

λ2 λ3 λ4

τ1 τ2 τ3 τ4

ε1

ε2

ε3

ε4

1*

0

Low moo

d

Tension

Psychological

Distress

λ1

Fatigue

Panic

λ2 λ3 λ4

τ1 τ2 τ3 τ4

ε1

ε2

ε3

ε4

1*

0

Low moo

d

Tension

Psychological

Distress

λ1

Fatigue

Panic

λ2 λ3 λ4

τ1 τ2 τ3 τ4

ε1

ε2

ε3

ε4

1*

0

Low moo

d

Tension

Psychological

Distress

λ1

Fatigue

Panic

λ2 λ3 λ4

τ1 τ2 τ3 τ4

ε1

ε2

ε3

ε4

1*

0

Low moo

d

Tension

Psychological

Distress

λ1

Fatigue

Panic

λ2 λ3 λ4

τ1 τ2 τ3 τ4

ε1

ε2

ε3

ε4

1*

0

Low moo

d

Tension

Psychological

Distress

λ1

Fatigue

Panic

λ2 λ3 λ4

τ1 τ2 τ3 τ4

ε1

ε2

ε3

ε4

1*

0

Low moo

d

Tension

Psychological

Distress

λ1

Fatigue

Panic

λ2 λ3 λ4

τ1 τ2 τ3 τ4

ε1

ε2

ε3

ε4

1*

0

Results – Comparisons across waves and cohorts

Goodness of fit criteriaChi-square (d.f.) RMSEA CFI TLI ΔRMSE

AΔCFI ΔTLI

NCDS 23, 33, 42, 50 Configural 1500.483 (216) 0.033 (0.031 to 0.034

0.988 0.984

Scalar 2482.448 (265) 0.039 (0.037 to 0.040)

0.979 0.977 0.006 0.009 0.007

BCS70 26, 30, 34, 42 Configural 1686.303 (216) 0.038 (0.036 to 0.039)

0.985 0.980

Scalar 2127.081 (265) 0.038 (0.037 to 0.040)

0.981 0.979 0.003 0.004 0.001

NCDS & BCS70 Configural 2354.305 (324) 0.035 (0.033 to 0.036)

0.986 0.981

Scalar 3775.376 (401) 0.040 (0.039 to 0.041)

0.976 0.974 0.005 0.010 0.007

(Ploubidis, McElroy & Moreira, manuscript accepted)

Results – Comparison across waves

(Ploubidis, McElroy & Moreira, manuscript accepted)

Results – Comparison across waves

(Ploubidis, McElroy & Moreira, manuscript accepted)

Results – Comparisons across waves and cohorts

0

2

4

6

8

10

12

14

16

18

-2.8

-2.6

-2.4

-2.2 -2

-1.8

-1.6

-1.4

-1.2 -1

-0.8

-0.6

-0.4

-0.2 0 0.2

0.4

0.6

0.8 1

1.2

1.4

1.6

1.8 2

2.2

2.4

2.6

2.8 3

3.2

NCDS23 NCDS33 NCDS42 BCS26 BCS34 BCS42

(Ploubidis, McElroy & Moreira, manuscript accepted)

Scale Information Functions for Mental Health Measures in NCDS

0

5

10

15

20

25-6

-5.6

-5.2

-4.8

-4.4 -4

-3.6

-3.2

-2.8

-2.4 -2

-1.6

-1.2

-0.8

-0.4 0 0.4 0.8 1.2 1.62

2.4 2.8 3.2 3.64

4.4 4.8 5.2 5.66

Malaise Age 23 Malaise Age 33 Malaise Age 42

Malaise Age 50 (9-item) GhQ-12 Age 42 SF-36 Age 50

HarmonisationNSHD NCDS BCS70

Age 36 Present State Examination (selected items)

Age 42 Malaise Inventory (24 items) Malaise (9 items)General Health Questionnaire (12-item) (GHQ-12)

Age 43Psychiatric Symptom Frequency Scale (18 items)

Age 46 Malaise (9 items)SF-36 (10 items)CES-D scale (Center for Epidemiologic Studies Depression) (10 items)

Age 50 Malaise Inventory (9 item)SF36

Age 53 General Health QuestionnaireAge 60-64 General Health Questionnaire

Age 69 General Health Questionnaire

Harmonisation

General Health Questionnaire (28-item) (GHQ-28)

Psychiatric Symptom Frequency Scale (18 items)

Present State Examination (selected items)

Malaise Inventory (9 item)

Low Mood17. Been able to enjoy your normal day-to-day activities

2. have you been in low spirits or felt miserable

20.Do you keep reasonably cheerful or have you been very depressed or low spirited recently? Have you cried at all? (Rate depressed mood)

2. Do you often feel miserable or depressed?

Fatigue 2. Been feeling in need of a good tonic14. have there been days when you tired out very easily?

3.Have you been exhausted and worn out during the day or evening even when you haven’t been working very hard? (rate tiredness/exhaustion) (slightly doubtful about this one)

1. Do you feel tired most of the time?

Tension 16. Felt constantly under strain1. have you felt on edge of keyed up or mentally tense

7.Do you often feel on edge, or keyed up, or mentally tense or strained? (rate nervous tension)

7. Are you constantly keyed up and jittery?

Panic19. Been getting scared or panicky for no good reason

8. have you been in situations when you felt shaky or sweaty or your heart pounded or you could not get your breath?

11.Have you had times when you felt shaky or you heart pounded or you felt sweaty and you simply had to do something about it? (rate panic attacks)

9. Does your heart often race like mad?

Results – Harmonised items across waves and cohorts

0

0.2

0.4

0.6

0.8

1

1.2

PSE Age 36 PSFS Age 43 GHQ Age 53 Malaise Age 42(24 item)

Malaise Age 50(9 item)

Malaise age 42(9 item)

Malaise age 46(9 item)

NSHD NCDS BCS

Results – Harmonised items across waves and cohorts

Goodness of fit criteriaChi-square

(d.f.)RMSEA CFI TLI ΔRMS

EAΔCFI ΔTLI

Model Configural 256.591 (18) 0.042 0.994 0.983Metric 383.003 (42) 0.033 0.992 0.990 0.009 0.002 0.007Scalar 4576.551 (66) 0.095 0.896 0.915 0.053 0.098 0.068Partial Scalar 1835.781 (58) 0.064 0.959 0.962 0.022 0.035 0.021Partial Scalar 2 775.514 (50) 0.044 0.983 0.982 0.002 0.011 0.001

Measurement properties

0

0.2

0.4

0.6

0.8

1

Mood Fatigue Tense Panic

NSHD NCDS BCS -1.4

-1.2

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

Mood Fatigue Tense Panic

NSHD NCDS BCS

Factor Loadings (λ) Thresholds (τ)

Teachers vs Mothers

Summary• Potential sources of bias such as age effects, survey

design, period effects, or cohort specific effects do not influence the way participants interpret and respond to mental health items

• Harmonised items are broadly representative of the scales they were derived from (capture the same construct)

• Teachers provide more reliable/precise reports on child mental health.

Outputs

Outputs

(Gondek et al., under review)

(Ploubidis et al., accepted, in press)

(McElroy et al., in prep)

(Villadsen et al., in prep)

Chart1

-2.8-2.8-2.8-2.8-2.8-2.8

-2.6-2.6-2.6-2.6-2.6-2.6

-2.4-2.4-2.4-2.4-2.4-2.4

-2.2-2.2-2.2-2.2-2.2-2.2

-2-2-2-2-2-2

-1.8-1.8-1.8-1.8-1.8-1.8

-1.6-1.6-1.6-1.6-1.6-1.6

-1.4-1.4-1.4-1.4-1.4-1.4

-1.2-1.2-1.2-1.2-1.2-1.2

-1-1-1-1-1-1

-0.8-0.8-0.8-0.8-0.8-0.8

-0.6-0.6-0.6-0.6-0.6-0.6

-0.4-0.4-0.4-0.4-0.4-0.4

-0.2-0.2-0.2-0.2-0.2-0.2

000000

0.20.20.20.20.20.2

0.40.40.40.40.40.4

0.60.60.60.60.60.6

0.80.80.80.80.80.8

111111

1.21.21.21.21.21.2

1.41.41.41.41.41.4

1.61.61.61.61.61.6

1.81.81.81.81.81.8

222222

2.22.22.22.22.22.2

2.42.42.42.42.42.4

2.62.62.62.62.62.6

2.82.82.82.82.82.8

333333

3.23.23.23.23.23.2

NCDS23

NCDS33

NCDS42

BCS26

BCS34

BCS42

1.00078

0.66765

1.10341

1.25629

0.92631

0.99931

1.00152

0.66771

1.10525

1.26227

0.92921

1.00172

1.00289

0.66783

1.10804

1.2718

0.93336

1.00595

1.00535

0.66809

1.11226

1.28677

0.93936

1.01343

1.00963

0.66862

1.1187

1.30988

0.94821

1.02664

1.01687

0.66971

1.12876

1.34481

0.96174

1.04977

1.02875

0.67185

1.14506

1.39637

0.98317

1.08953

1.04769

0.67603

1.17254

1.47048

1.01796

1.15578

1.07702

0.68394

1.22003

1.57405

1.07481

1.2617

1.12116

0.69843

1.30215

1.71456

1.16621

1.42265

1.18567

0.72403

1.44057

1.89959

1.30807

1.65354

1.27727

0.76745

1.66281

2.13625

1.51747

1.96515

1.40365

0.83787

1.9967

2.43076

1.80875

2.36162

1.57309

0.94674

2.46001

2.78812

2.18922

2.84241

1.79383

1.10686

3.04888

3.21176

2.65792

3.41015

2.07316

1.33077

3.73291

3.70304

3.20985

4.08022

2.41616

1.62902

4.46386

4.26086

3.84464

4.88182

2.82421

2.00887

5.19694

4.88238

4.57277

5.84052

3.29372

2.47441

5.91323

5.56655

5.41155

6.94612

3.81627

3.02806

6.62969

6.32016

6.36811

8.12715

4.3821

3.6738

7.38945

7.16003

7.41453

9.25241

4.9883

4.42143

8.23156

8.09782

8.46223

10.15618

5.64783

5.28536

9.14125

9.09625

9.34729

10.66927

6.38541

6.25837

9.99698

10.01447

9.85071

10.65329

7.20016

7.24425

10.5628

10.60272

9.77622

10.04903

7.99759

7.99564

10.57748

10.60136

9.06011

8.92278

8.55419

8.18054

9.91251

9.90401

7.83118

7.46584

8.60262

7.61315

8.6736

8.64745

6.35925

5.9287

8.01867

6.43657

7.14779

7.13801

4.92709

4.52911

6.93773

5.0302

5.64463

5.68266

3.72248

3.39262

4.46685

2.80989

2.54887

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1.65.647835.285369.141259.096259.3472910.669271.87324

1.86.385416.258379.9969810.014479.8507110.653292.05236

27.200167.2442510.562810.602729.7762210.049032.23148

2.27.997597.9956410.5774810.601369.060118.922782.4106

2.48.554198.180549.912519.904017.831187.465842.58973

2.68.602627.613158.67368.647456.359255.92872.76885

2.88.018676.436577.147797.138014.927094.529112.94797

36.937735.03025.644635.682663.722483.392623.12709

3.24.466852.809892.548873.30621

NCDS23

NCDS33

NCDS42

NCDS23

NCDS33

NCDS42

BCS26

BCS34

BCS42

TrainNCDSWomen23Women23Women33Women42

1.04741

-1.407811.716491.048481.54104

-1.254531.728251.050461.5538

-1.101251.74831.054141.57463

-0.947971.781231.060891.60803

-0.794691.833271.073171.66026

-0.641411.912331.094991.73951

-0.488132.027691.132711.8556

-0.334852.189251.195572.01917

-0.181572.406271.29592.24041

-0.028292.685951.448352.52781

0.124993.032251.667842.88753

0.278273.44551.966393.32417

0.431553.923252.350033.8425

0.584834.461992.817534.44842

0.738115.058863.362615.14657

0.891395.711623.978925.93405

1.044676.41684.665276.79477

1.197957.168145.428177.70389

1.351237.959976.28158.64868

1.504518.797257.24189.65408

1.657799.703218.3090910.77479

1.8110710.702249.4195712.01559

1.9643511.7621610.3879213.20646

2.1176312.7227510.9129413.96342

2.2709113.2905610.7114713.8618

2.4241913.161969.7152612.73973

2.5774712.217458.1518110.85043

2.7307510.625866.417978.70283

2.884038.758614.862286.75563

3.037316.990483.655785.23386

Women23

Women33

Women42

Outputs

Harmonisation of mental health measures in British birth cohortsAcknowledgementsAcknowledgementsOutline Slide Number 5Harmonisation Harmonisation HarmonisationHarmonisationMeasurement properties: AimsMeasurement propertiesMeasurement propertiesMeasurementMeasurementReliability/precision: Scale Information FunctionResults – Comparisons across waves and cohorts Results – Comparisons across waves and cohorts Results – Comparisons across waves and cohorts Results – Comparison across waves Results – Comparison across waves Results – Comparisons across waves and cohorts Scale Information Functions for Mental Health Measures in NCDSHarmonisationHarmonisationResults – Harmonised items across waves and cohorts Results – Harmonised items across waves and cohorts Measurement propertiesTeachers vs MothersSlide Number 29SummaryOutputs Outputs Outputs Slide Number 34