Understanding Society User Support

Dear Luca,

In Wave 1 respondents were asked to report whether they’d ever been diagnosed with clinical depression and whether at that time they still had the condition (w_hcond17 and w_hconds17). At each subsequent interview (i.e., wave), they were only asked about any new diagnoses (w_hcondn17, the ‘n’ in the name meaning new) – meaning that, perhaps importantly for you, diagnoses from previous waves were not followed up to ascertain whether they still had the condition. The variables w_hcond17 and w_hconds17 have been collected since Wave 3 but this is for new entrants to the study: at subsequent interviews they are only asked about new diagnoses too.

You may be interested in the GHQ score of mental health that is collected in every wave, although this is a subjective measure and possibly not ideal for your purposes (although it could be argued that someone’s assessment of whether they still have a previously diagnosed condition is somewhat subjective too). This module was part of the self-completion paper questionnaire at waves 1 and 2, as you can download here https://www.understandingsociety.ac.uk/documentation/mainstage/questionnaires, and you can see it in the online documentation of the scaghq module from wave 3 onwards: https://www.understandingsociety.ac.uk/documentation/mainstage/dataset-documentation/wave/3/questionnaire-module/scaghq_w3

You may also be interested to know that we are currently developing the questionnaire to collect information about previous diagnoses, including whether the respondent reports still having such conditions. This information should be available from Wave 10 onwards. In some types of analyses the presence of post-diagnosis symptoms/conditions is not important, it is the diagnosis that’s relevant (it’s objective, it signals the likely presence of an underlying condition even if symptoms are either not currently present or managed via medication, etc.). However this is not sufficient for all research questions and we are revising our data collection strategy.

Best wishes,
Stephanie Auty - Understanding Society User Support Officer

---------- Forwarded message ----------
From: Bernardi, Luca <lb350@leicester.ac.uk>
Date: Fri, Sep 8, 2017 at 9:50 AM
Subject: Re: [Understanding Society User Support - Support #848] Clinical Depression H_COND variables
To: "info@understandingsociety.ac.uk" <info@understandingsociety.ac.uk>

Dear Stephanie,

Many thanks for your super quick reply and for better explaining the situation with the variables of interest.

Best wishes,
Luca

From: Bernardi, Luca [mailto:lb350@leicester.ac.uk]
Sent: 08 September 2017 10:05
To: Auty, Stephanie
Subject: Understanding Society Issue #848

Dear Stephanie,

Thank you again for getting back to me so quickly.

Sorry for contacting you directly to your email address, but I wanted to make sure I understand what it is sensible to do and what is not. Given that the hcond17, hconds17 and hcondn17 questions are not asked in all waves contemporaneously, does my proposal of using information from all variables make sense? Note that in this particular project I am not doing a panel study but I am simply pooling the data so I am not interested in tracking respondents over time.

I recall that what I had in mind is to create a dummy variable for depression equals 1 if the person replied positively to the hconds17 and hcondn17 questions and equals 0 if the person replied negatively to the hcond17 and hcondn17 questions.
Otherwise, what I was previously doing is to use data only from the hcond17 and hconds17 questions, in which case Wave 2 was not included in the analysis. Hence, what I was doing is to to create a dummy variable for depression equals 1 if the person replied positively to the hconds17 question and equals 0 if the person replied negatively to the hcond17 question.

As you know the data much better than I do, I would really appreciate if you could let me know if both solutions are feasible or only the latter is.

Thanks and best wishes,
Luca

Dear Luca,

These are valid questions. It would be helpful if you could post your reply on the User Forum (https://www.understandingsociety.ac.uk/support/projects/support) as
(i) we manage and track these requests and make sure someone from the team answers within 10 working days
(ii) we send these requests to the person best suited to answer that particular question
(iii) and most importantly other users can benefit from the answers. Similarly, you can search on the User Forum to see if someone has raised this issue before.

I will follow your reply on the forum with my answer as below, so that other users can benefit.

The variables you are discussing measure different things, and we don’t know the respondents’ current status. We can’t tell you what assumptions to make as it depends on your research question. Our remit at the User Forum is to answer queries related to Understanding Society data and provide general advice about how to manage the data. Given the number of users we have I'm afraid we cannot advise on individual users' analysis specifically.

The new entrants at each wave are not part of the original sample. They provide a household context for the OSMs and also increase the sample size, which compensates somewhat for attrition. So if you didn’t include wave 2 new entrants it would not impact on how representative your analysis is.

If you would like to discuss weighting based on this then I can assign this issue to Peter Lynn after we have posted our replies on the forum.

There are two other variables you could look at, w_hcondno1-10 and w_hcondns1-10 from wave 2 onwards (not all waves have 10 of these variables). These measure whether the respondent still has their new diagnosis as asked in w_hcondn, but which variable is related to depression varies depending on which conditions the respondent has.

Best wishes,
Stephanie

From: Bernardi, Luca (Dr.) [mailto:lb388@leicester.ac.uk]
Sent: 04 October 2017 14:23
To: Auty, Stephanie
Subject: Re: Understanding Society Issue #848

Dear Stephanie,

I am replying from this account because I have just changed email. Many thanks for your message. Please feel free to post our exchange on the forum if this can be of help for other researchers and sorry for not having done this myself immediately. So if I understand correctly your point on the representativeness of the analysis, I should be ok on this side even without including Wave 2, am I right? If so, that is good news. I appreciate that you cannot offer suggestions that depend on the research question, but since the depressive sample declines considerably after Wave 1, I would be grateful if you could please advice me on whether it still makes sense to use data from subsequent waves or if I am good enough with only Wave 1.

I think forwarding the message to Peter Lynn is a great idea and thanks for this, because it would be very helpful for my analysis to know whether to use a weight would be more appropriate than not weighting at all, given the low N of depressive respondents compared to non-sufferers. I look forward to Peter's reply and yours.

Best wishes,
Luca

Luca,

I will try to answer some of your questions in terms of weighting. But please if my response is not sufficient do not hesitate to rephrase and ask again.

In terms of representation you are fine if
1. you just use wave 1 - this is completely fine - just use the cross-sectional weight relevant to your analysis;
2. if you pool your data over the waves but exclude wave 2 - this is again completely fine from the perspective of population representation. You should use cross-sectional weight relevant to your analysis from each wave in your analysis. Because with time the sample size varies (due to attrition and refreshments) - you should add a scaling factor so that each wave contributes to the analysis similar to other waves. Read this note on how to create the scaling factor: https://www.understandingsociety.ac.uk/support/issues/494 . Also please remember to indicate clustering within respondents - otherwise the statistical program will think that you have much higher sample than you actually do.

Hope this helps,
Olena