General study and participant information [Version 5]

Title of the study: Influence of established and subjectively perceived and assessed individual characteristics on the utilisation behaviour of people with depressive disorders? A longitudinal study to complement the "Behavioural Model of Health Services Use" and to demand-congruent utilisation

Welcome to our study "Influence of established and subjectively perceived and evaluated individual characteristics on the utilisation behaviour of people with depressive disorders? A longitudinal study to complement the "Behavioural Model of Health Services Use" and on demand-congruent utilisation. To enable us to provide you with detailed information about our study, we would be grateful if you would take the time to read the following pages.

The data collection is complete! We would like to thank all participants of the study for their support!

Purpose(s) of the study
Around 20 out of 100 people suffer from depression in the course of their lives. Only about one in three people suffering from depression seek help from the healthcare system for these problems. In order to improve healthcare, it is important to investigate the reasons for non-utilisation.

The first survey was completed at the end of November 2020 and 925 people from all over Germany took part. The second survey round will start in April 2021. All participants in the first survey will be contacted and interviewed again by telephone by the social and opinion research institute USUMA GmbH approximately 12 months after the first interview. In addition, up to 32 people will be interviewed in person by staff from the University of Oldenburg. This study serves scientific research purposes.

Study procedure
As only interviews are conducted as part of the study, there are no medical risks associated with participation. The interviews are about psychological complaints.

Your participation in this study will not benefit your health. However, the results of this study may help to improve the care of people with mental health complaints.

We commissioned USUMA GmbH to conduct the two telephone interviews. Your telephone number wasselected at random using the ADM telephone sampling system(www.adm-ev.de/leistungen/arbeitsgemeinschaft-adm-stichproben/). To process your data during the two telephone interviews and to contact you, we have concluded a so-called order processing contract with USUMA GmbH in accordance with Art. 28 GDPR. This means that USUMA GmbH processes your personal data on behalf of the controller and must also comply with the strict data protection provisions of the GDPR. At the beginning of the first telephone interview, we asked you nine questions to determine whether you fall into the group to be analysed by the study. If this was the case, we then asked you more detailed questions about mental health complaints and the use of health services. After completing the first wave of the survey, USUMA GmbH donated a total of €1,000 to the Foundation for Mental Health. This foundation is particularly committed to projects aimed at counteracting the stigmatisation of people with mental health complaints. By taking part, you are not only contributing to scientific knowledge, but also supporting the Foundation for Mental Health's projects.

If you have provided your address or email address at the end of the first telephone interview, we will send you answer lists (lists of problems and complaints) by post or email shortly before the second telephone interview, which you may need to answer certain questions in the second telephone interview. Please keep these lists close to your telephone until the second call from the USUMA GmbH staff. If you receive the lists digitally by email, it would be good if you could either print them out or save them so that you can access them during the second telephone interview. The second interview will last around 45 minutes and will take place approximately one year after the first telephone interview. You will also receive more detailed information about the planned face-to-face interviews, which will take place with up to 32 people, with the letter/email. This information is also available for download on this page (file: "EIN-IMDE written study information personal interview").

The telephone interviews will not be recorded. Only the answers you give to the questions asked will be noted. After the second telephone interview, up to 32 people will be selected for more detailed interviews. If you give your consent at the end of the second telephone interview, the selected persons will be contacted by employees of the University of Oldenburg and appointments for personal interviews will be arranged. If the coronavirus situation allows, it is possible to conduct the interview with you at the University of Oldenburg. There is then a hygiene concept adapted to the current situation, which both you as the interviewee and we as interviewers must adhere to. If a face-to-face interview is not possible or not desired by you, we will conduct the interviews by video call or telephone. In any case, you will receive an expense allowance. If you decide to travel to the University of Oldenburg, you will be insured on the way there and back and on site and your travel expenses will be reimbursed. Before the start of the personal interview, we will inform you again and obtain your written consent. If you are interested, you can find further information on this possible third interview in the written study information (file: "EIN-IMDE written study information personal interview").

Categories of personal data that are processed

In the context of this study, depending on the categorisation according to a so-called PHQ-9 value [1]various personal data will be collected from you. This value was already determined in the first telephone call with you. In any case, your telephone number and Federal State as well as your age, gender and health data will be recorded - at least for a short time - according to the so-called PHQ-9 test.

If you are one of the 925 people who exceeded a certain threshold value at the beginning of the first interview (PHQ9 value ≥ 5), we will ask you further questions in the course of the two interviews using scientifically established questionnaires[2] will be asked. In these questionnaires, you will essentially provide further health data in connection with your mental health complaints and your care utilisation behaviour. You can find out which specific data is collected and processed in the respective questionnaires either in advance or during the survey. You do not have to answer every question and can cancel the survey at any time. We will also process your contact details (name, address, telephone number) for the purpose of contacting you at a later date, provided you consent to this. We will only process your billing data (name, address, date, amount paid, purpose of payment, bank details) if you take part in one of the maximum 32 personal interviews.

Voluntariness and anonymity
Participation is voluntary for you. It will only take place with your consent given over the phone. You can cancel your participation in this study at any time without giving reasons and without incurring any disadvantages. The data and personal information collected as part of these studies and described above will be treated confidentially. The confidentiality of your data is guaranteed at all times and all persons involved have given a corresponding commitment to confidentiality. Furthermore, the results of the study will only be published in anonymised form. This means that the data can no longer be attributed to a specific person.

Duration of the study
The study lasts around 1.5 years. The telephone interviews last up to 60 minutes, with the first telephone interview being shorter. The personal third interview in Oldenburg or via video call/on the phone will take about 45 minutes.

Data processing procedure
We will create a multi-digit combination of letters or numbers, also known as a code, in order to be able to match your details in the second telephone interview with the details in the first telephone interview. The code will be assigned to your telephone number on a separate coding list, which will be stored on USUMA GmbH data carriers. Only USUMA GmbH employees have access to the key, which enables the personal assignment of the survey data to your telephone number. This list is not stored together with interview data. This allows USUMA GmbH to contact you for the second telephone interview and we, the study group at the University of Oldenburg, can assign your details to those from the first telephone interview using the code.

At the end of the second telephone interview, you can also give your separate consent for USUMA GmbH to pass on your code and your contact details to Dr Brütt and her staff. This will enable Dr Brütt and her staff to identify people for in-depth interviews based on their analyses and to contact you. In this case, the data will be anonymised following the third personal interview. Further information on this can be found in the written study information (file: "EIN-IMDE study information personal interviews").

If you do not give your consent to participate in a personal interview, the data collected will be forwarded to the study group at the University of Oldenburg in anonymised form after the second telephone interview has been completed. This is done electronically in encrypted form. At the University of Oldenburg, the data will be analysed by PD Dr Brütt and her staff in accordance with the research question of the study.

You can withdraw your consent at any time without giving reasons. Until the data has been anonymised, you can decide whether your data that has already been collected should be deleted or may continue to be used in anonymised form. After anonymisation, it is no longer possible to assign your data to you personally and therefore no longer possible to delete individual data.

Duration of storage
After completion of the data collection (second telephone interview or personal interview), the coding list is deleted and further analysis is anonymised. The anonymised data will be stored at the University of Oldenburg, Ammerländer Heerstraße 140, 26129 Oldenburg for 10 years and then permanently deleted.

After completion of the first telephone interview, USUMA GmbH will forward your pseudonymised address data to PD Dr Brütt and her staff. At this point, they will not be able to assign your health data to you personally. Only contact data with your address and name will be transmitted (without pseudonymisation codes). After completion of this interim procedure (receipt of the response lists and written information about the personal qualitative interviews), the project staff will delete your address data.

USUMA GmbH will delete the coding list after completion of the second telephone interview and transmission of the complete personal data to PD Dr Brütt and her staff for evaluation. It will then no longer be possible for USUMA GmbH to assign your data to you personally.

If you receive an expense allowance, your billing data will be processed by Division 2 for billing purposes. For this reason, Division 2: Finances of the University of Oldenburg is authorised to access your billing data. Your billing data must be kept by Division 2 for at least 10 years in accordance with Section 147 of the German Fiscal Code.

Use of the data
This study is for research purposes only. Your data will not be passed on to third parties.

Data protection
Contact details of those responsible and their data protection officer