Objectives: Norwegian health authorities require all long-term care institutions to determine and record whether residents should have cardiopulmonary resuscitation (CPR) administered in the case of an emergency. There is a need to better understand variation in CPR-status using population level data to obtain accurate estimates and to understand how it differs by cultural and socioeconomic status. Design: Population register based assessments. Setting and Participants: This study investigate the proportions of CPR+ and CPR- . by age, gender, marital status, primary contact and care needs in a sample that include all residents in long-term care facilities in Oslo aged 50 years or older (N = 11,948) during the period 1st of January 2018 to 31st of December 2023. Everyone in the dataset had CPR status. Methods: Descriptive population-level assessment of health care residents' registry data and logistic regression analyses. Results: The proportion of residents who were CPR+ was slightly below one third (31.4%), with significantly more women (33,2%) than men (27.9%). CPR+ decreased with age (45.9% for those aged 50-66 years, 27.4% for those aged 85-89 years) but rose again for the oldest age group (33.0%, aged 90+). Compared to unmarried individuals and widows or widowers, the proportion of married long-term care residents with CPR+ was lower. Those who had no primary contact or more distant ones (e.g., a lawyer) were more likely to be CPR+. The CPR+ was slightly higher among individuals with comprehensive care needs. However, the differences were only significant for CPR+ among those with comprehensive care needs compared to those with moderate care needs when adjusted for age, gender, and primary contact. Conclusions and Implications: Only one third of long-term care residents in Norway are registered as CPR+. Particularly women and those at younger ages and the oldest old were more likely to be CPR+. The low proportions of CPR+ residents across major segments of Norway's institutionalized population as well as gender and age distribution will hopefully spark debates about CPR practices.

The authors have declared no competing interest.

This study is based on adminstrative records.

We acknowledge support from the Research Council of Norway (Centres of Excellence-nr 262700), from the National Institutes of Health-NIH, R01: R01AG069109-01 and an ERC Advanced Grant Project ? 101142786 ? HOMME.

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 Nursing Home Agency in Oslo Municipality has approved the use of anonymized data extracted from the Norwegian patient record system for long term residents at care homes (Gerica) for research (Ref. No. 21/1691-2, dated June 14, 2021).

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, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

The Nursing Home Agency in Oslo Municipality gave written approval to use the anonymized data extracted from the Norwegian patient record system for long term residents at care homes (Gerica) for research (Ref. No. 21/1691-2, dated June 14, 2021).