Potential organ donors during two years at the second largest hospital in Norway.

BACKGROUND: Western Norway has the lowest number of actual deceased organ donors per million inhabitants in Norway. We wished to find the total number of potential donors and donor organs during 2 years at Haukeland University Hospital, the largest hospital in the region, and evaluate where and why potential donors were lost. METHODS: We evaluated all patients who died at Haukeland University Hospital in 2018-19. We checked if intensive care patients, filling the criteria as organ donors after brain death, became donors, and the reasons why potential donors were lost. We also estimated the number of potential donors after circulatory death. We checked if patients transferred from the intensive care units and patients never admitted to intensive care were potential donors. Location, gender, age, and possible number of organs were registered. RESULTS: Of 1453 in-hospital deaths, 20 brain-dead patients became actual donors. One brain-dead and two other potential donors, one of them discharged to a bed ward, were not evaluated at the intensive care units. Relatives refused in five patients. Three fulfilled the Norwegian criteria from 2021 as organ donors after circulatory death. Ten potential donors after brain death were never admitted to intensive care and died on neurological or neurosurgical wards. If all potential organ donors were realised, the number of donors would double. The number of transplanted organs would increase less, as organs used per donor would drop from 3.50 to 2.90. CONCLUSION: Our study cannot explain the low number of donors in our region compared with the rest of Norway. If all potential donations were implemented, the number of actual donors would double. Patients dying outside the intensive care units represent the largest potential source for extra donors, maximally increasing the number of donors by 42%, high-quality livers 44% and kidneys 18%. Introducing organ donation after circulatory death may increase the number of donors by 15% and the number of high-quality livers and kidneys by 12%.

Platelet transfusions in adult ICU patients with thrombocytopenia: A sub-study of the PLOT-ICU inception cohort study.

BACKGROUND: Platelet transfusions are frequently used in the intensive care unit (ICU), but current practices including used product types, volumes, doses and effects are unknown. STUDY DESIGN AND METHODS: Sub-study of the inception cohort study 'Thrombocytopenia and Platelet Transfusions in the ICU (PLOT-ICU)', including acutely admitted, adult ICU patients with thrombocytopenia (platelet count <150 × 109/L). The primary outcome was the number of patients receiving platelet transfusion in ICU by product type. Secondary outcomes included platelet transfusion details, platelet increments, bleeding, other transfusions and mortality. RESULTS: Amongst 504 patients with thrombocytopenia from 43 hospitals in 10 countries in Europe and the United States, 20.8% received 565 platelet transfusions; 61.0% received pooled products, 21.9% received apheresis products and 17.1% received both with a median of 2 (interquartile range 1-4) days from admission to first transfusion. The median volume per transfusion was 253 mL (180-308 mL) and pooled products accounted for 59.1% of transfusions, however, this varied across countries. Most centres (73.8%) used fixed dosing (medians ranging from 2.0 to 3.5 × 1011 platelets/transfusion) whilst some (mainly in France) used weight-based dosing (ranging from 0.5 to 0.7 × 1011 platelets per 10 kg body weight). The median platelet count increment for a single prophylactic platelet transfusion was 2 (-1 to 8) × 109/L. Outcomes of patients with thrombocytopenia who did and did not receive platelet transfusions varied. CONCLUSIONS: Among acutely admitted, adult ICU patients with thrombocytopenia, 20.8% received platelet transfusions in ICU of whom most received pooled products, but considerable variation was observed in product type, volumes and doses across countries. Prophylactic platelet transfusions were associated with limited increases in platelet counts.

A first-level customization study of SAPS II with Norwegian Intensive Care and Pandemic Registry (NIPaR) data.

BACKGROUND: Severity scores and mortality prediction models (MPMs) are important tools for benchmarking and stratification in the intensive care unit (ICU) and need to be regularly updated using data from a local and contextual cohort. Simplified acute physiology score II (SAPS II) is widely used in European ICUs. METHODS: A first-level customization was performed on the SAPS II model using data from the Norwegian Intensive Care and Pandemic Registry (NIPaR). Two previous SAPS II models (Model A: the original SAPS II model and Model B: a SAPS II model based on NIPaR data from 2008 to 2010) were compared to the new Model C. Model C was based on patients from 2018 to 2020 (corona virus disease 2019 patients omitted; n = 43,891), and its performances (calibration, discrimination, and uniformity of fit) compared to the previous models (Model A and Model B). RESULTS: Model C was better calibrated than Model A with a Brier score 0.132 (95% confidence interval 0.130-0.135) versus 0.143 (95% confidence interval 0.141-0.146). The Brier score for Model B was 0.133 (95% confidence interval 0.130-0.135). In the Cox's calibration regression α ≈ 0 and ß ≈ 1 for both Model C and Model B but not for Model A. Uniformity of fit was similar for Model B and for Model C, both better than for Model A, across age groups, sex, length of stay, type of admission, hospital category, and days on respirator. The area under the receiver operating characteristic curve was 0.79 (95% confidence interval 0.79-0.80), showing acceptable discrimination. CONCLUSIONS: The observed mortality and corresponding SAPS II scores have significantly changed during the last decades and an updated MPM is superior to the original SAPS II. However, proper external validation is required to confirm our findings. Prediction models need to be regularly customized using local datasets in order to optimize their performances.

The Nordic perioperative and intensive care registries-Collaboration and research possibilities.

BACKGROUND: The Nordic perioperative and intensive care registries have been built up during the last 25 years to improve quality in intensive and perioperative care. We aimed to describe the Nordic perioperative and intensive care registries and to highlight possibilities and challenges in future research collaboration between these registries. MATERIAL AND METHOD: We present an overview of the following Nordic registries: Swedish Perioperative Registry (SPOR), the Danish Anesthesia Database (DAD), the Finnish Perioperative Database (FIN-AN), the Icelandic Anesthesia Database (IS-AN), the Danish Intensive Care Database (DID), the Swedish Intensive Care Registry (SIR), the Finnish Intensive Care Consortium, the Norwegian Intensive Care and Pandemic Registry (NIPaR), and the Icelandic Intensive Care Registry (IS-ICU). RESULTS: Health care systems and patient populations are similar in the Nordic countries. Despite certain differences in data structure and clinical variables, the perioperative and intensive care registries have enough in common to enable research collaboration. In the future, even a common Nordic registry could be possible. CONCLUSION: Collaboration between the Nordic perioperative and intensive care registries is both possible and likely to produce research of high quality. Research collaboration between registries may have several add-on effects and stimulate international standardization regarding definitions, scoring systems, and benchmarks, thereby improving overall quality of care.

A survey of preferences for respiratory support in the intensive care unit for patients with acute hypoxaemic respiratory failure.

BACKGROUND: When caring for mechanically ventilated adults with acute hypoxaemic respiratory failure (AHRF), clinicians are faced with an uncertain choice between ventilator modes allowing for spontaneous breaths or ventilation fully controlled by the ventilator. The preferences of clinicians managing such patients, and what motivates their choice of ventilator mode, are largely unknown. To better understand how clinicians' preferences may impact the choice of ventilatory support for patients with AHRF, we issued a survey to an international network of intensive care unit (ICU) researchers. METHODS: We distributed an online survey with 32 broadly similar and interlinked questions on how clinicians prioritise spontaneous or controlled ventilation in invasively ventilated patients with AHRF of different severity, and which factors determine their choice. RESULTS: The survey was distributed to 1337 recipients in 12 countries. Of these, 415 (31%) completed the survey either fully (52%) or partially (48%). Most respondents were identified as medical specialists (87%) or physicians in training (11%). Modes allowing for spontaneous ventilation were considered preferable in mild AHRF, with controlled ventilation considered as progressively more important in moderate and severe AHRF. Among respondents there was strong support (90%) for a randomised clinical trial comparing spontaneous with controlled ventilation in patients with moderate AHRF. CONCLUSIONS: The responses from this international survey suggest that there is clinical equipoise for the preferred ventilator mode in patients with AHRF of moderate severity. We found strong support for a randomised trial comparing modes of ventilation in patients with moderate AHRF.

Respiratory dysfunction three months after severe COVID-19 is associated with gut microbiota alterations.

BACKGROUND: Although coronavirus disease 2019 (COVID-19) is primarily a respiratory infection, mounting evidence suggests that the gastrointestinal tract is involved in the disease, with gut barrier dysfunction and gut microbiota alterations being related to disease severity. Whether these alterations persist and are related to long-term respiratory dysfunction remains unknown. METHODS: Plasma was collected during hospital admission and after 3 months from the NOR-Solidarity trial (n = 181) and analyzed for markers of gut barrier dysfunction and inflammation. At the 3-month follow-up, pulmonary function was assessed by measuring the diffusing capacity of the lungs for carbon monoxide (DLCO ). Rectal swabs for gut microbiota analyses were collected (n = 97) and analyzed by sequencing the 16S rRNA gene. RESULTS: Gut microbiota diversity was reduced in COVID-19 patients with respiratory dysfunction, defined as DLCO below the lower limit of normal 3 months after hospitalization. These patients also had an altered global gut microbiota composition, with reduced relative abundance of 20 bacterial taxa and increased abundance of five taxa, including Veillonella, potentially linked to fibrosis. During hospitalization, increased plasma levels of lipopolysaccharide-binding protein (LBP) were strongly associated with respiratory failure, defined as pO2 /fiO2 (P/F ratio) <26.6 kPa. LBP levels remained elevated during and after hospitalization and were associated with low-grade inflammation and respiratory dysfunction after 3 months. CONCLUSION: Respiratory dysfunction after COVID-19 is associated with altered gut microbiota and persistently elevated LBP levels. Our results should be regarded as hypothesis generating, pointing to a potential gut-lung axis that should be further investigated in relation to long-term pulmonary dysfunction and long COVID.

A descriptive study of the surge response and outcomes of ICU patients with COVID-19 during first wave in Nordic countries.

BACKGROUND: We sought to provide a description of surge response strategies and characteristics, clinical management and outcomes of patients with severe COVID-19 in the intensive care unit (ICU) during the first wave of the pandemic in Denmark, Finland, Iceland, Norway and Sweden. METHODS: Representatives from the national ICU registries for each of the five countries provided clinical data and a description of the strategies to allocate ICU resources and increase the ICU capacity during the pandemic. All adult patients admitted to the ICU for COVID-19 disease during the first wave of COVID-19 were included. The clinical characteristics, ICU management and outcomes of individual countries were described with descriptive statistics. RESULTS: Most countries more than doubled their ICU capacity during the pandemic. For patients positive for SARS-CoV-2, the ratio of requiring ICU admission for COVID-19 varied substantially (1.6%-6.7%). Apart from age (proportion of patients aged 65 years or over between 29% and 62%), baseline characteristics, chronic comorbidity burden and acute presentations of COVID-19 disease were similar among the five countries. While utilization of invasive mechanical ventilation was high (59%-85%) in all countries, the proportion of patients receiving renal replacement therapy (7%-26%) and various experimental therapies for COVID-19 disease varied substantially (e.g. use of hydroxychloroquine 0%-85%). Crude ICU mortality ranged from 11% to 33%. CONCLUSION: There was substantial variability in the critical care response in Nordic ICUs to the first wave of COVID-19 pandemic, including usage of experimental medications. While ICU mortality was low in all countries, the observed variability warrants further attention.

Milder disease trajectory among COVID-19 patients hospitalised with the SARS-CoV-2 Omicron variant compared with the Delta variant in Norway.

Using individual-level national registry data, we conducted a cohort study to estimate differences in the length of hospital stay, and risk of admission to an intensive care unit and in-hospital death among patients infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant, compared with patients infected with Delta variant in Norway. We included 409 (38%) patients infected with Omicron and 666 (62%) infected with Delta who were hospitalised with coronavirus disease 2019 (COVID-19) as the main cause of hospitalisation between 6 December 2021 and 6 February 2022. Omicron patients had a 48% lower risk of intensive care admission (adjusted hazard ratios (aHR): 0.52, 95% confidence interval (CI): 0.34-0.80) and a 56% lower risk of in-hospital death (aHR: 0.44, 95%CI: 0.24-0.79) compared with Delta patients. Omicron patients had a shorter length of stay (with or without ICU stay) compared with Delta patients in the age groups from 18 to 79 years and those who had at least completed their primary vaccination. This supports growing evidence of reduced disease severity among hospitalised Omicron patients compared with Delta patients.

Reduced risk of hospitalisation among reported COVID-19 cases infected with the SARS-CoV-2 Omicron BA.1 variant compared with the Delta variant, Norway, December 2021 to January 2022.

We included 39,524 COVID-19 Omicron and 51,481 Delta cases reported in Norway from December 2021 to January 2022. We estimated a 73% reduced risk of hospitalisation (adjusted hazard ratio: 0.27; 95% confidence interval: 0.20-0.36) for Omicron compared with Delta. Compared with unvaccinated groups, Omicron cases who had completed primary two-dose vaccination 7-179 days before diagnosis had a lower reduced risk than Delta (66% vs 93%). People vaccinated with three doses had a similar risk reduction (86% vs 88%).

Characteristics, management and survival of ICU patients with coronavirus disease-19 in Norway, March-June 2020. A prospective observational study.

BACKGROUND: Norwegian hospitals have operated within capacity during the COVID-19 pandemic. We present patient and management characteristics, and outcomes for the entire cohort of adult (>18 years) COVID-19 patients admitted to Norwegian intensive care units (ICU) from 10 March to 19 June 2020. METHODS: Data were collected from The Norwegian intensive care and pandemic registry (NIPaR). Demographics, co-morbidities, management characteristics and outcomes are described. ICU length of stay (LOS) was analysed with linear regression, and associations between risk factors and mortality were quantified using Cox regression. RESULTS: In total, 217 patients were included. The male to female ratio was 3:1 and the median age was 63 years. A majority (70%) had one or more co-morbidities, most frequently cardiovascular disease (39%), chronic lung disease (22%), diabetes mellitus (20%), and obesity (17%). Most patients were admitted for acute hypoxaemic respiratory failure (AHRF) (91%) and invasive mechanical ventilation (MV) was used in 86%, prone ventilation in 38% and 25% of patients received a tracheostomy. Vasoactive drugs were used in 79% and renal replacement therapy in 15%. Median ICU LOS and time of MV was 14.0 and 12.0 days. At end of follow-up 45 patients (21%) were dead. Age, co-morbidities and severity of illness at admission were predictive of death. Severity of AHRF and male gender were associated with LOS. CONCLUSIONS: In this national cohort of COVID-19 patients, mortality was low and attributable to known risk factors. Importantly, prolonged length-of-stay must be taken into account when planning for resource allocation for any next surge.

The provision of nurse-led follow-up at Norwegian intensive care units.

AIMS AND OBJECTIVES: To describe the prevalence, content and administration of intensive care unit diaries and follow-up practices offered to patients and their families in Norway. BACKGROUND: Intensive care treatment has been associated with risks for new or increased health impairments affecting both patients and their families. These impairments have the potential of continuing beyond the acute phase of treatment. In parallel, preventive actions have gradually become an integrated part of critical care nursing, and in Norway, national recommendations for the use of intensive care unit diaries have been established. DESIGN AND METHODS: A survey was conducted in Norwegian intensive care units offering care for adult patients, using a questionnaire asking about the frequency, administration and content of the follow-up offered to patients, their relatives, as well as bereaved family members. RESULTS: Thirty-nine of 66 (59.1%) invited intensive care units answered the questionnaire. The majority (n = 33, 84.6%) of the responding units had follow-up routines. The provision of diaries was the most frequent follow-up activity (n = 24, 61.5%), and consultations postdischarge formed an integrated part of the diary practice. Consultations with bereaved were conducted in 21 (53.8%) of the intensive care units. About one quarter of the responding intensive care units had positions for follow-up nursing staff. CONCLUSION: Nurse-led follow-up after critical care was a common activity in Norwegian intensive care units, comprising diaries and consultations offered to patients and family members. The follow-up was mainly driven by bottom-up processes conducted by dedicated nurses motivated by the patients' and their families' situation and feedback. RELEVANCE TO CLINICAL PRACTICE: Adherence to recommendations, as well as the availability of defined positions for aftercare nurses or teams, may improve the implementation of follow-up practices and reduce suffering after discharge from Norwegian intensive care units.

Long-Term Outcomes After ICU Admission Triage in Octogenarians.

OBJECTIVE: To describe ICU admission triage and outcomes in octogenarians. DESIGN: Multicenter prospective observational study. SETTING: Three nonuniversity hospitals and three university hospitals in Norway. PATIENTS: Patients 80 years old or older who were referred for ICU admission from November 2013 to October 2014. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the 355 included patients, 105 (29.6%) were refused ICU treatment. Risk factors for ICU refusal in patients considered "too ill/old" were advanced age and low functional status. Risk factors for ICU refusal in patients considered "too well" were advanced age, male sex, university hospital admission, comorbidity, and low Simplified Acute Physiology Score 3. Overall ICU survival was 71.6%. Hospital and 1-year survival were 56.0% and 40.0% in the ICU-admitted, 65.2% and 50.0% in the nonadmitted patients considered too well, and 32.7% and 11.5% in patients considered too ill/old, respectively. The adjusted Kaplan-Meier curves showed significantly lower survival for nonadmitted patients considered too ill/old than for ICU-admitted patients and nonadmitted patients considered too well. At follow-up, triage patients had lower health-related quality of life than an age- and sex-matched control group in the domains of self-care, usual care, and anxiety and depression, and a lower EuroQol visual analog scale scores. CONCLUSIONS: Overall, 29.6% of the patients were refused ICU treatment. The adjusted survival analyses showed a significantly higher survival for ICU-admitted octogenarians than for nonadmitted patients who were considered too ill/old, indicating a benefit of ICU admission. Overall, the follow-up of triage patients showed lower health-related quality of life than an age- and sex-matched control population.

Costs and expected gain in lifetime health from intensive care versus general ward care of 30,712 individual patients: a distribution-weighted cost-effectiveness analysis.

BACKGROUND: Clinicians, hospital managers, policy makers, and researchers are concerned about high costs, increased demand, and variation in priorities in the intensive care unit (ICU). The objectives of this modelling study are to describe the extra costs and expected health gains associated with admission to the ICU versus the general ward for 30,712 patients and the variation in cost-effectiveness estimates among subgroups and individuals, and to perform a distribution-weighted economic evaluation incorporating extra weighting to patients with high severity of disease. METHODS: We used a decision-analytic model that estimates the incremental cost per quality-adjusted life year (QALY) gained (ICER) from ICU admission compared with general ward care using Norwegian registry data from 2008 to 2010. We assigned increasing weights to health gains for those with higher severity of disease, defined as less expected lifetime health if not admitted. The study has inherent uncertainty of findings because a randomized clinical trial comparing patients admitted or rejected to the ICU has never been performed. Uncertainty is explored in probabilistic sensitivity analysis. RESULTS: The mean cost-effectiveness of ICU admission versus ward care was €11,600/QALY, with 1.6 QALYs gained and an incremental cost of €18,700 per patient. The probability (p) of cost-effectiveness was 95% at a threshold of €22,000/QALY. The mean ICER for medical admissions was €10,700/QALY (p = 97%), €12,300/QALY (p = 93%) for admissions after acute surgery, and €14,700/QALY (p = 84%) after planned surgery. For individualized ICERs, there was a 50% probability that ICU admission was cost-effective for 85% of the patients at a threshold of €64,000/QALY, leaving 15% of the admissions not cost-effective. In the distributional evaluation, 8% of all patients had distribution-weighted ICERs (higher weights to gains for more severe conditions) above €64,000/QALY. High-severity admissions gained the most, and were more cost-effective. CONCLUSIONS: On average, ICU admission versus general ward care was cost-effective at a threshold of €22,000/QALY (p = 95%). According to the individualized cost-effectiveness information, one in six ICU admissions was not cost-effective at a threshold of €64,000/QALY. Almost half of these admissions that were not cost-effective can be regarded as acceptable when weighted by severity of disease in terms of expected lifetime health. Overall, existing ICU services represent reasonable resource use, but considerable uncertainty becomes evident when disaggregating into individualized results.

COVID-19 and venous thromboembolism - prophylaxis and treatment. / Covid-19 og venøs tromboembolisme ­ profylakse og behandling.

As the pandemic has been unfolding, reports have emerged of a relatively high incidence of coagulopathy and thromboembolic events in connection with COVID-19 infections. Raised awareness surrounding this issue, and appropriate antithrombotic prophylaxis and treatment, are therefore important for this group of patients.

Thrombocytopenia and platelet transfusions in ICU patients: an international inception cohort study (PLOT-ICU).

PURPOSE: Thrombocytopenia (platelet count < 150 × 109/L) is common in intensive care unit (ICU) patients and is likely associated with worse outcomes. In this study we present international contemporary data on thrombocytopenia in ICU patients. METHODS: We conducted a prospective cohort study in adult ICU patients in 52 ICUs across 10 countries. We assessed frequencies of thrombocytopenia, use of platelet transfusions and clinical outcomes including mortality. We evaluated pre-selected potential risk factors for the development of thrombocytopenia during ICU stay and associations between thrombocytopenia at ICU admission and 90-day mortality using pre-specified logistic regression analyses. RESULTS: We analysed 1166 ICU patients; the median age was 63 years and 39.5% were female. Overall, 43.2% (95% confidence interval (CI) 40.4-46.1) had thrombocytopenia; 23.4% (20-26) had thrombocytopenia at ICU admission, and 19.8% (17.6-22.2) developed thrombocytopenia during their ICU stay. Absence of acquired immune deficiency syndrome (AIDS), non-cancer-related immune deficiency, liver failure, male sex, septic shock, and bleeding at ICU admission were associated with the development of thrombocytopenia during ICU stay. Among patients with thrombocytopenia, 22.6% received platelet transfusion(s), and 64.3% of in-ICU transfusions were prophylactic. Patients with thrombocytopenia had higher occurrences of bleeding and death, fewer days alive without the use of life-support, and fewer days alive and out of hospital. Thrombocytopenia at ICU admission was associated with 90-day mortality (adjusted odds ratio 1.7; 95% CI 1.19-2.42). CONCLUSION: Thrombocytopenia occurred in 43% of critically ill patients and was associated with worse outcomes including increased mortality. Platelet transfusions were given to 23% of patients with thrombocytopenia and most were prophylactic.

Length of hospital stay and risk of intensive care admission and in-hospital death among COVID-19 patients in Norway: a register-based cohort study comparing patients fully vaccinated with an mRNA vaccine to unvaccinated patients.

OBJECTIVES: We estimated the length of stay (LoS) in hospital and the intensive care unit (ICU) and risk of admission to ICU and in-hospital death among COVID-19 patients ≥18 years in Norway who had been fully vaccinated with an mRNA vaccine (at least two doses or one dose and previous SARS-CoV-2 infection), compared to unvaccinated patients. METHODS: Using national registry data, we analyzed SARS-CoV-2-positive patients hospitalized in Norway between 1 February and 30 November 2021, with COVID-19 as the main cause of hospitalization. We ran Cox proportional hazards models adjusting for vaccination status, age, sex, county of residence, regional health authority, date of admission, country of birth, virus variant, and underlying risk factors. RESULTS: We included 716 fully vaccinated patients (crude overall median LoS: 5.2 days; admitted to ICU: 103 (14%); in-hospital death: 86 (13%)) and 2487 unvaccinated patients (crude overall median LoS: 5.0 days; admitted to ICU: 480 (19%); in-hospital death: 102 (4%)). In adjusted models, fully vaccinated patients had a shorter overall LoS in hospital (adjusted log hazard ratios (aHR) for discharge: 1.61, 95% CI: 1.24-2.08), shorter LoS without ICU (aHR: 1.27, 95% CI: 1.07-1.52), and lower risk of ICU admission (aHR: 0.50, 95% CI: 0.37-0.69) compared to unvaccinated patients. We observed no difference in the LoS in ICU or in risk of in-hospital death between fully vaccinated and unvaccinated patients. DISCUSSION: Fully vaccinated patients hospitalized with COVID-19 in Norway have a shorter LoS and lower risk of ICU admission than unvaccinated patients. These findings can support patient management and ongoing capacity planning in hospitals.

No difference in risk of hospitalization between reported cases of the SARS-CoV-2 Delta variant and Alpha variant in Norway.

OBJECTIVES: To estimate the risk of hospitalization among reported cases of the Delta variant of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) compared with the Alpha variant in Norway, and the risk of hospitalization by vaccination status. METHODS: A cohort study was conducted on laboratory-confirmed cases of SARS-CoV-2 in Norway, diagnosed between 3 May and 15 August 2021. Adjusted risk ratios (aRR) with 95% confidence intervals (CI) were calculated using multi-variable log-binomial regression, accounting for variant, vaccination status, demographic characteristics, week of sampling and underlying comorbidities. RESULTS: In total, 7977 cases of the Delta variant and 12,078 cases of the Alpha variant were included in this study. Overall, 347 (1.7%) cases were hospitalized. The aRR of hospitalization for the Delta variant compared with the Alpha variant was 0.97 (95% CI 0.76-1.23). Partially vaccinated cases had a 72% reduced risk of hospitalization (95% CI 59-82%), and fully vaccinated cases had a 76% reduced risk of hospitalization (95% CI 61-85%) compared with unvaccinated cases. CONCLUSIONS: No difference was found between the risk of hospitalization for Delta cases and Alpha cases in Norway. The results of this study support the notion that partially and fully vaccinated cases are highly protected against hospitalization with coronavirus disease 2019.