1. GHQ-12 Able to concentrate Lost much sleep Playing a useful part
Capable of making decisions
Under stress
Could not overcome difficulties
Enjoy normal activities
Can face up to problems
Feeling unhappy and depressed
Losing confidence
Thinking of self as worthless
Feeling reasonably happy
INSTRUCTIONS
We should like to know if you have any medical complaints, and how your health has been in general, over the past few weeks…..
We want to know about present and recent complaints, not those you had in the past.

2. 12 item GHQ (6 positive items)
able to enjoy day-to-day activities
More so than usual MSTU
Same as usual SAU
Less so than usual LSTU
Much less than usual MTLU
Item 8
able to face up to your problems
Less able than usual LATU
Item 12
feeling reasonably happy all things considered
Item 1
able to concentrate
Better than usual BTU
Same as usual SAU
Less than usual LTU
Much less than usual MTLU
Item 3
playing a useful part
More so than usual MSTU
Less useful than usual LUTU
Item 4
felt capable of making decisions
Less so than usual LSTU
Much less capable MLC

3. 12 item GHQ (6 negative items)
feeling unhappy and depressed
Not at all NAA
No more than usual NMTU
Rather more than usual RMTU
Much more than usual MMTU
Item 10
been losing confidence in yourself
Item 11
thinking of self as worthless person
Item 2
lost much sleep over worry
Not at all NAA
No more than usual NMTU
Rather more than usual RMTU
Much more than usual MMTU
Item 5
playing a usefu part
Item 6
felt capable of making decisions

4. ILLEGAL & WRONG !!!

5. Goldberg’s GHQ-12: BHPS VARIABLE & RESPONSE LABELS
ighqa : ghq: concentration
1: better than usual
2: same as usual
3: less than usual
4: much less thn usual
ighqb : ghq: loss of sleep
1: not at all
2: no more than usual
3: rather more thn usul
4: much more than usual
ighqc : ghq: playing a useful role
1: more than usual
3: less so
4: much less
ighqd : ghq: capable of making decisions
ighqe : ghq: constantly under strain
3: rather more
4: much more
ighqf : ghq: problem overcoming difficulties
ighqg : ghq: enjoy day-to-day activities
1: more than usual
2: same as usual
3: less so
4: much less
ighqh : ghq: ability to face problems
ighqi : ghq: unhappy or depressed
1: not at all
2: no more thn usual
3: rather more
4: much more
ighqj : ghq: losing confidence
2: no more than usual
ighqk : ghq: believe in self-worth
ighql : ghq: general happiness

6. Duncan-Jones et al (1986), Psych Med Goldberg et al (1987) Psych Med
Latent Goldberg: What kinds of models are required to ask what research questions?
Q … the characteristics and performance of GHQ items as measures of distress, and the estimated or assumed dist’n of the latent trait
Q … the potential for some items to be scored to capture a notion of positive mental health. Does the GHQ “do” well-being?
Psychiatry
Psychology
Focus on negative items
Normal ogive item response models WLS
Logistic distribution item response models ML
Focus on GHQ positive items
Equal interval scoring as Interval?
Coding “more than usual” ve items
Latent variable model (IRT/LTA or CDFA)
Discrimination & Difficulty params ICCs
Information function (effective measurement)
Scoring methods for -ve items (cGHQ)
Model-based vs simple sum score (linear models, interval (metric) scores)
Person (cluster) vs variable centered analyses
IRT models with ordinal or nominal indicators
Standard statistical approach - under applied Novel scoring approaches, under-validated
Duncan-Jones et al (1986), Psych Med
Goldberg et al (1987) Psych Med
Whittington & Huppert (2003) SSM
Ploubidis et al (2007) P&ID

8. Positively worded items scored 1000
GHQ01
GHQ03
GHQ04
GHQ07
GHQ08
GHQ12 F1
GHQ
Pos F2
GHQ
Neg
Orthogonal
GHQ02
GHQ05
GHQ06
GHQ09
GHQ10
GHQ11
Negatively items scored 0011

10. Setting the scene Software use: what do you use? SPSS SAS STATA
R/Splus MATLAB
Specialist: Psychometric
BILOG MULTILOG TESTFACT PARSCALE
Rasch software

11. Psychometric papers
What statistics/statistical analyses do you associate with a “psychometric” paper
What would you use a computer to calculate for you?
Why are you doing that? Why only that?
What else could you do and how?
Increasing your options and understanding of the range of psychometric scaling approaches and statistic analyses
Psychometric analyses, and increasing the accuracy with which you describe, execute and combine them

12. Example: GHQ General Health Questionnaire See GHQ Users Guide and Goodchild-Duncan Jones (Ref pdf)
This instrument has no numbers on it
Scoring begins from assignment of
1, 2, 3, 4
(weights)
i.e. consecutive integers
to the ordered levels
of the graded responses [Scoring methods alter weights/Scaling models estimate weights]
Be careful with question wording
GHQ is balanced in terms of
+ & - question wording
[what does this mean?]
Why – and what implication(s)?
NB: If response options are consistently (re)-worded, this avoids the need for reverse scoring]

14. GHQ-30 data from a population survey: HALS (Baseline)

15. GHQ-30 data from a population survey: HALS (9 items)

19. New portable C:\HALS_CGHQ_negativeonly.dta

22. Time to share out well tested
Data preparation pipeline
(semi-automated)
Take it away Jon