Objective: The aim of this study was to provide gender, age, and morbidity specific Norwegian general population normative values for the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaires QLQ C30, the sexual health questionnaire QLQ SHQ22, and the sexual domains of the breast modules QLQ BR23 and QLQ BR45. Methods: A random nation-wide sample stratified by gender and age groups (18 to 29, 30 to 39, 40 to 49, 50 to 59, 60 to 69 and 70 to 79 years) was drawn from the Norwegian National Population Register. Participants were notified through National online health services (HelseNorge) and by postal mail. The survey included sociodemographic background information, HRQoL assessed by the EORTC questionnaires, and morbidity by The Self Administered Comorbidity Questionnaire. Multivariable linear regression was carried out to estimate the associations of age, sex, and morbidity with the EORTC scale and item scores. Results: Of the 15,627 eligible individuals, 5.135 (33%) responded. Women and persons with morbidities reported lower functioning and higher symptom burden than men and persons without morbidities, respectively, on nearly all EORTC scales. Sex differences were most prominent for Emotional Functioning, Pain, Fatigue, and Insomnia (QLQ C30), Body Image, Sexual Functioning (QLQ BR23/45), Importance of Sexual Activity, Libido, and Fatigue (QLQ SHQ22). The score differences between persons with and without morbidity were highly significant and largest among the youngest and middle-aged groups. Conclusion: The present study is the first to provide normative values for the EORTC sexual health questionnaire QLQ SHQ22 and the sexual subscales of the QLQ BR23 and QLQ BR45, for all separately in age groups by sex and morbidity.

The authors have declared no competing interest.

This study was funded by the Norwegian Cancer Society, the Norwegian Breast Cancer Society and The Norwegian University of Science and Technology

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The study was approved by the Ethics Committee of Central Norway, Regional Committee for Medical Research Ethics (REK numbers 2020/58888). Study information was enclosed to the survey with completion regarded as informed consent.

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

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I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.

Yes

All data produced in the present study are available upon reasonable request to the authors