For people living with HIV

You may have found this page because you were told that information from your care is used in research, or because you heard about COSMOHS from your clinic or from a patient organisation. This page explains what the study is, what it does with information about you, and what your options are.

What the study is about

People living with HIV in Sweden today can expect a life expectancy close to that of everyone else. But research suggests that many people live with more illness along the way — heart disease, diabetes, certain cancers — and report poorer quality of life, even when their HIV treatment is working well. It is not yet clear how much of this is caused by HIV itself, and how much by the same things that affect everyone's health: age, heredity, income, working conditions, where you were born, and access to care.

COSMOHS was set up to separate these threads. Understanding them is the first step towards better care, earlier prevention and better quality of life for people living with HIV.

What information is used

The study uses information that already exists. No one will contact you, ask you questions or take new samples.

For everyone in the study — both people living with HIV and people without HIV — the information comes from Sweden's national registers: hospital diagnoses and visits, cancer diagnoses, prescribed medicines, causes of death, and background information such as age, sex, country of birth, education and income. For people living with HIV, information from InfCareHIV is also used, including CD4 counts, viral load, HIV treatment, and answers to the health questionnaire about quality of life.

How your privacy is protected

Researchers never see your name or personal identity number. Data are pseudonymised (anonymised for the recipient) before they reach the research group, so each person is represented only by an index number, and the key that connects index numbers to personal identity numbers is held by Statistics Sweden, not by the researchers. Results are only ever published at group level, and nothing that could identify an individual is published. The data are stored on a secured server at Karolinska Institutet, with access granted only to named researchers approved by the principal investigator. The study has been approved by the Swedish Ethical Review Authority (decision number 2023-00191-01, with amendments 2024-04185-02, 2025-01207-02 and 2026-01254-02).

Your choices

Everyone diagnosed with HIV in Sweden is informed about InfCareHIV at the time of diagnosis, and told that data may be used for research if ethical approval has been granted. You have the right to opt out of InfCareHIV. If you want to do so, or if you want to know what is registered about you, speak to your HIV clinic.

The national registers held by Statistics Sweden and the National Board of Health and Welfare work differently. Their use for research is regulated by Swedish law — the Patient Data Act and the Public Access to Information and Secrecy Act — which permits health data to be used for research without individual consent, provided that ethical approval has been granted. This applies to the whole population, not only to people living with HIV. Asking every one of 9 million people for consent would not be possible, and would also distort the results, since the people who consented would not be representative of everyone else.

What you get from it

We want to be straightforward about this: there is no direct benefit to you as an individual from taking part. The benefit is collective and it is longer-term. We believe the results will give real insight into comorbidity among people living with HIV — a problem that affects a great many people — and that this can improve care in the future. The findings on quality of life may also inform future guidelines and preventive measures.