Performance of quantitative measures of multimorbidity: a population-based retrospective analysis.

BACKGROUND: Multimorbidity measures are useful for resource planning, patient selection and prioritization, and factor adjustment in clinical practice, research, and benchmarking. We aimed to compare the explanatory performance of the adjusted morbidity group (GMA) index in predicting relevant healthcare outcomes with that of other quantitative measures of multimorbidity. METHODS: The performance of multimorbidity measures was retrospectively assessed on anonymized records of the entire adult population of Catalonia (North-East Spain). Five quantitative measures of multimorbidity were added to a baseline model based on age, gender, and socioeconomic status: the Charlson index score, the count of chronic diseases according to three different proposals (i.e., the QOF, HCUP, and Karolinska institute), and the multimorbidity index score of the GMA tool. Outcomes included all-cause death, total and non-scheduled hospitalization, primary care and ER visits, medication use, admission to a skilled nursing facility for intermediate care, and high expenditure (time frame 2017). The analysis was performed on 10 subpopulations: all adults (i.e., aged > 17 years), people aged > 64 years, people aged > 64 years and institutionalized in a nursing home for long-term care, and people with specific diagnoses (e.g., ischemic heart disease, cirrhosis, dementia, diabetes mellitus, heart failure, chronic kidney disease, and chronic obstructive pulmonary disease). The explanatory performance was assessed using the area under the receiving operating curves (AUC-ROC) (main analysis) and three additional statistics (secondary analysis). RESULTS: The adult population included 6,224,316 individuals. The addition of any of the multimorbidity measures to the baseline model increased the explanatory performance for all outcomes and subpopulations. All measurements performed better in the general adult population. The GMA index had higher performance and consistency across subpopulations than the rest of multimorbidity measures. The Charlson index stood out on explaining mortality, whereas measures based on exhaustive definitions of chronic diagnostic (e.g., HCUP and GMA) performed better than those using predefined lists of diagnostics (e.g., QOF or the Karolinska proposal). CONCLUSIONS: The addition of multimorbidity measures to models for explaining healthcare outcomes increase the performance. The GMA index has high performance in explaining relevant healthcare outcomes and may be useful for clinical practice, resource planning, and public health research.

What lies beneath: a retrospective, population-based cohort study investigating clinical and resource-use characteristics of institutionalized older people in Catalonia.

BACKGROUND: Planning population care in a specific health care setting requires deep knowledge of the clinical characteristics of the target care recipients, which tend to be country specific. Our area virtually lacks any descriptive, far-reaching publications about institutionalized older people (IOP). We aimed to investigate the demographic and clinical characteristics of institutionalized older people (IOP) ≥65 years old and compare them with those of the rest of the population of the same age. METHODS: Retrospective analysis (total cohort approach) of clinical and resource-use characteristics of IOP and non-IOP older than 65 years in Catalonia (North-East Spain). Variables analysed included age and sex, diagnoses, morbidity burden-using Adjusted Morbidity Groups (GMA, Grupos de Morbilidad Ajustada)-, mortality, use of resources, and medications taken. All data were obtained from the administrative database of the local healthcare system. RESULTS: This study included 93,038, 78,458, 68,545 and 67,456 IOP from 2011, 2013, 2015 and 2017, respectively. In this interval, an increase in median age (83 vs. 87 years), in women (68.64% vs. 72.11%) and in annual mortality (11.74% vs. 20.46%) was observed. Compared with non-IOP (p < 0.001 in all comparisons), IOP showed a higher annual mortality (20.46% vs. 3.13%), a larger number of chronic diseases (specially dementia: 46.47% vs. 4.58%), higher multimorbidity (15.2% vs. 4.2% with GMA of maximum complexity), and annual admissions to acute care (47.6% vs. 27.7%) and skilled nursing facilities (27.8% vs. 7.4%), mean length of hospital stay (10.0 vs. 7.2 days) and mean of medications taken (11.7 vs. 8.0). CONCLUSIONS: There is a growing gap between the clinical and demographic characteristics of age-matched IOP and non-IOP, which overlaps with a higher mortality rate of IOP. The profile of resources utilization of IOP compared with non-IOP strongly suggests a deficiency of preventive actions and stresses the need to rethink the care model for IOP from a social and health care perspective.

[Clinical validation of 2 morbidity groups in the primary care setting]. / Validación clínica de 2 agrupadores de morbilidad en el ámbito de atención primaria.

INTRODUCTION: Adjusted Morbidity Groups (GMAs) and the Clinical Risk Groups (CRGs) are population morbidity based stratification tools which classify patients into mutually exclusive categories. OBJETIVE: To compare the stratification provided by the GMAs, CRGs and that carried out by the evaluators according to the levels of complexity. DESIGN: Random sample stratified by morbidity risk. LOCATION: Catalonia. PARTICIPANTS: Forty paired general practitioners in the primary care, matched pairs. INTERVENTIONS: Each pair of evaluators had to review 25 clinical records. MAIN OUTPUTS: The concordance by evaluators, and between the evaluators and the results obtained by the 2 morbidity tools were evaluated according to the kappa index, sensitivity, specificity, and positive and negative predicted values. RESULTS: The concordance between general practitioners pairs was around the kappa value 0.75 (mean value=0.67), between the GMA and the evaluators was similar (mean value=0.63), and higher than for the CRG (mean value=0.35). The general practitioners gave a score of 7.5 over 10 to both tools, although for the most complex strata, according to the professionals' assignment, the GMA obtained better scores than the CRGs. The professionals preferred the GMAs over the CRGs. These differences increased with the complexity level of the patients according to clinical criteria. Overall, less than 2% of serious classification errors were found by both groupers. CONCLUSION: The evaluators considered that both grouping systems classified the studied population satisfactorily, although the GMAs showed a better performance for more complex strata. In addition, the clinical raters preferred the GMAs in most cases.

Socioeconomic status, life expectancy and mortality in a universal healthcare setting: An individual-level analysis of >6 million Catalan residents.

We evaluated the association between individual-level socioeconomic status (SES), life expectancy, and mortality, in adult men and women from the general population living in Catalonia, a universal healthcare coverage setting. We used the Catalan Health Surveillance System database, which includes individual-level information on sociodemographic characteristics and mortality for all residents of Catalonia (Spain). We categorized individuals as high, medium, low or very low SES based on annual personal income and welfare receipt. We used 2016 mortality data to estimate life expectancy at age 18, and the probability of death by age, sex and SES categories. We followed a total of 6,027,424 Catalan residents in 2016. Men and women of very low SES had 12.0 and 9.4 years lower life expectancy compared to men and women of high SES, respectively. Low SES was also strongly associated with mortality in both men and women of any age. In the entire adult population of Catalonia, despite the availability of universal, high quality healthcare coverage, low SES is associated with lower life expectancy and higher mortality. Solutions to these large inequalities may combine tailored health promotion and management interventions, with solutions coming from outside of the health sector.

[Validity of adjusted morbidity groups with respect to clinical risk groups in the field of primary care]. / Validez de los grupos de morbilidad ajustados respecto a los clinical risk groups en el ámbito de la atención primaria.

OBJECTIVE: To compare the performance in terms of goodness of fit and explanatory power of 2morbidity groupers in primary care (PC): adjusted morbidity groups (AMG) and clinical risk groups (CRG). DESIGN: Cross-sectional study. LOCATION: PC in the Catalan Institute for the Health (CIH), Catalonia, Spain. PARTICIPANTS: Population allocated in primary care centers of the CIH for the year 2014. MAIN MEASUREMENTS: Three indicators of interest are analyzed such as urgent hospitalization, number of visits and spending in pharmacy. A stratified analysis by centers is applied adjusting generalized lineal models from the variables age, sex and morbidity grouping to explain each one of the 3variables of interest. The statistical measures to analyze the performance of the different models applied are the Akaike index, the Bayes index and the pseudo-variability explained by deviance change. RESULTS: The results show that in the area of the primary care the explanatory power of the AMGs is higher to that offered by the CRGs, especially for the case of the visits and the pharmacy. CONCLUSIONS: The performance of GMAs in the area of the CIH PC is higher than that shown by the CRGs.

Challenges of evaluating chronic heart failure and acute heart failure events in research studies using large health care databases.

Epidemiological studies on heart failure (HF) using large health care databases are becoming increasingly frequent, as they represent an invaluable opportunity to characterize the importance and risk factors of HF from a population perspective. Nevertheless, because of its complex diagnosis and natural history, the heterogeneous use of the relevant terminology in routine clinical practice, and the limitations of some disease coding systems, HF can be a challenging condition to assess using large health care databases as the main source of information. In this narrative review, we discuss some of the challenges that researchers may face, with a special focus on the identification and validation of chronic HF cases and acute HF decompensations. For each of these challenges, we present some potential solutions inspired by the literature and/or based on our research experience, aimed at increasing the internal validity of research and at informing its interpretation. We also discuss future directions on the field, presenting constructive recommendations aimed at facilitating the conduct of valid epidemiological studies on HF in the coming years.

[Adjusted morbidity groups: A new multiple morbidity measurement of use in Primary Care]. / Los grupos de morbilidad ajustados: nuevo agrupador de morbilidad poblacional de utilidad en el ámbito de la atención primaria.

The Adjusted Morbidity Groups (GMA) is a new morbidity measurement developed and adapted to the Spanish healthcare System. It enables the population to be classified into 6 morbidity groups, and in turn divided into 5 levels of complexity, along with one healthy population group. Consequently, the population is divided into 31 mutually exclusive categories. The results of the stratification in Catalonia are presented. GMA is a method for grouping morbidity that is comparable to others in the field, but has been developed with data from the Spanish health system. It can be used to stratify the population and to identify target populations. It has good explanatory and predictive results in the use of health resources indicators. The Spanish Ministry of Health is promoting the introduction of the GMA into the National Health System.

Hospital mortality over time in patients with specific complications of cirrhosis.

UNLABELLED: Hospital mortality secondary to cirrhosis is high. AIM: To evaluate hospital mortality in patients admitted for specific complications of cirrhosis over time. MATERIAL AND METHODS: Registry-data from Administrative Inpatient Dataset of acute care hospitals were collected at discharge from 2003 to 2010. Inclusion criteria were as follows: hospital admissions where one of the diagnoses was cirrhosis and the reason for admission was a specific complication of cirrhosis (ascites, encephalopathy, hepatorenal syndrome and haemorrhage from varices, bacterial spontaneous peritonitis). Analysis of variance was used for comparisons of quantitative variables and Chi-square for qualitative variables. Logistic regression was performed to identify the risk factors associated with hospital mortality; the Hosmer and Lemeshow test was applied to evaluate calibration and the ROC curve for discrimination respectively. RESULTS: A total of 12,671 hospital admissions were analysed; 67.7% were men. Mean hospitalization stay was 10.9 (SD 9.2) days and the most frequent causes were encephalopathy (44.2%) and ascites (30.9%). Global hospital mortality was 11.6%. Logistic regression showed that once all factors had been adjusted, hepatorenal syndrome conveyed the highest risk for death (49.2%; OR = 8.1(95%CI:6.6-9.9). Risk of death was also increased by associated comorbidities and older age. Hospital mortality in the period 2006-2010 was 27% inferior to the period 2003-2005. The area under the ROC curve (AUROC) was 0.77 (95%CI 0.76-0.78). CONCLUSIONS: Hospital mortality as a result of specific complications of cirrhosis is high, but has been declining in recent years.

Implications of the 2021 ESC cardiovascular risk classification among 283,000 European immigrants living in a low-risk region: a population-based analysis in Catalonia.

Introduction: The ESC recently classified European countries into 4 cardiovascular risk regions. However, whether Europeans from higher-risk countries living in lower-risk regions may benefit from intensive cardiovascular prevention efforts is unknown. We described the burden of risk factors and cardiovascular disease (CVD) among European-born immigrants living in Catalonia, a low-risk region. Material and methods: A retrospective cohort study of 5.6 million adults of European origin living in Catalonia in 2019, including 282,789 European-born immigrants, was performed. We used the regionwide healthcare database and classified participants into 5 groups: low-, moderate-, high-, and very high-risk, and local-born. Age-standardized prevalence was estimated as of December 31st, 2019 and incidence was computed during 2019 among at-risk individuals. Results: The very high-risk group was the largest immigrant group (N = 136,910; 48.4%), while the high-risk group was the smallest (N = 15,739; 5.6%). These two had the highest burden of coronary heart disease across all groups evaluated, in both men and women. The very high-risk group also had the highest prevalence of hypertension and obesity at young-to-middle age, and the burden of risk factors newly diagnosed during 2019 was highest in high- and very high-risk participants. The mean age at first diagnosis of risk factors and CVD was lower in these groups. Conclusions: In Catalonia, residents born in high- and very-high-risk European countries are at increased risk of coronary heart disease and newly diagnosed risk factors. Low-risk European countries may consider tailored prevention efforts, early screening of risk factors, and adequate healthcare resource planning to better address the health needs of men and women from higher-risk countries.

Is Age the Most Important Risk Factor in COVID-19 Patients? The Relevance of Comorbidity Burden: A Retrospective Analysis of 10,551 Hospitalizations.

Purpose: To assess the contribution of age and comorbidity to the risk of critical illness in hospitalized COVID-19 patients using increasingly exhaustive tools for measuring comorbidity burden. Patients and Methods: We assessed the effect of age and comorbidity burden in a retrospective, multicenter cohort of patients hospitalized due to COVID-19 in Catalonia (North-East Spain) between March 1, 2020, and January 31, 2022. Vaccinated individuals and those admitted within the first of the six COVID-19 epidemic waves were excluded from the primary analysis but were included in secondary analyses. The primary outcome was critical illness, defined as the need for invasive mechanical ventilation, transfer to the intensive care unit (ICU), or in-hospital death. Explanatory variables included age, sex, and four summary measures of comorbidity burden on admission extracted from three indices: the Charlson index (17 diagnostic group codes), the Elixhauser index and count (31 diagnostic group codes), and the Queralt DxS index (3145 diagnostic group codes). All models were adjusted by wave and center. The proportion of the effect of age attributable to comorbidity burden was assessed using a causal mediation analysis. Results: The primary analysis included 10,551 hospitalizations due to COVID-19; of them, 3632 (34.4%) experienced critical illness. The frequency of critical illness increased with age and comorbidity burden on admission, irrespective of the measure used. In multivariate analyses, the effect size of age decreased with the number of diagnoses considered to estimate comorbidity burden. When adjusting for the Queralt DxS index, age showed a minimal contribution to critical illness; according to the causal mediation analysis, comorbidity burden on admission explained the 98.2% (95% CI 84.1-117.1%) of the observed effect of age on critical illness. Conclusion: Comorbidity burden (when measured exhaustively) explains better than chronological age the increased risk of critical illness observed in patients hospitalized with COVID-19.

Inequalities by Income in the Prevalence of Cardiovascular Disease and Its Risk Factors in the Adult Population of Catalonia.

Background Understanding the magnitude of cardiovascular disease (CVD) inequalities is the first step toward addressing them. The linkage of socioeconomic and clinical data in universal health care settings provides critical information to characterize CVD inequalities. Methods and Results We employed a prospective cohort design using electronic health records data from all residents of Catalonia aged 18+ between January and December of 2019 (N=6 332 228). We calculated age-adjusted sex-specific prevalence of 5 CVD risk factors (diabetes, hypertension, hyperlipidemia, obesity, and smoking), and 4 CVDs (coronary heart disease, cerebrovascular disease, atrial fibrillation, and heart failure). We categorized income into high, moderate, low, and very low according to individual income (tied to prescription copayments) and receipt of welfare support. We found large inequalities in CVD and CVD risk factors among men and women. CVD risk factors with the largest inequalities were diabetes, smoking, and obesity, with prevalence rates 2- or 3-fold higher for those with very low (versus high) income. CVDs with the largest inequalities were cerebrovascular disease and heart failure, with prevalence rates 2 to 4 times higher for men and women with very low (versus high) income. Inequalities varied by age, peaking at midlife (30-50 years) for most diseases, while decreasing gradually with age for smoking. Conclusions We found wide and heterogeneous inequalities by income in 5 CVD risk factors and 4 CVD. Our findings in a region with a high-quality public health care system and universal coverage stress that strong equity-promoting policies are necessary to reduce disparities in CVD.

Changes in Treatment Patterns and Costs for Lung Cancer Have Not Resulted in Relevant Improvements in Survival: A Population-Based Observational Study in Catalonia.

OBJECTIVE: Few published studies have described multidisciplinary therapeutic strategies for lung cancer. This study aims to describe the different approaches used for treating lung cancer in Catalonia in 2014 and 2018 and to assess the associated cost and impact on patient survival. METHODS: A retrospective observational cohort study using data of patients with lung cancer from health care registries in Catalonia was carried out. We analyzed change in treatment patterns, costs and survival according to the year of treatment initiation (2014 vs. 2018). The Kaplan-Meier method was used to estimate survival, with the follow-up until 2021. RESULTS: From 2014 to 2018, the proportion of patients undergoing surgery increased and treatments for unresectable tumors decreased, mainly in younger patients. Immunotherapy increased by up to 9% by 2018. No differences in patient survival were observed within treatment patterns. The mean cost per patient in the first year of treatment increased from EUR 14,123 (standard deviation [SD] 4327) to EUR 14,550 (SD 3880) in surgical patients, from EUR 4655 (SD 3540) to EUR 5873 (SD 6455) in patients receiving curative radiotherapy and from EUR 4723 (SD 7003) to EUR 6458 (SD 10,116) in those treated for unresectable disease. CONCLUSIONS: From 2014 to 2018, surgical approaches increased in younger patients. The mean cost of treating patients increased, especially in pharmaceutical expenditure, mainly related to the use of several biomarker-targeted treatments. While no differences in overall patient survival were observed, it seems reasonable to expect improvements in this outcome in upcoming years as more patients receive innovative treatments.

Burden of cardiovascular risk factors and disease in five Asian groups in Catalonia: a disaggregated, population-based analysis of 121 000 first-generation Asian immigrants.

AIMS: To evaluate the burden of cardiovascular risk factors and disease (CVD) among five Asian groups living in Catalonia (Spain): Indian, Pakistani, Bangladeshi, Filipino, and Chinese. METHODS AND RESULTS: Retrospective cohort study using the Catalan Health Surveillance System database including 42 488 Pakistanis, 40 745 Chinese, 21 705 Indians, 9544 Filipinos, and 6907 Bangladeshis; and 5.3 million native individuals ('locals'). We estimated the age-adjusted prevalence (as of 31 December 2019) and incidence (during 2019) of diabetes, hypertension, hyperlipidaemia, obesity, tobacco use, coronary heart disease (CHD), cerebrovascular disease, atrial fibrillation, and heart failure (HF). Bangladeshis had the highest prevalence of diabetes (17.4% men, 22.6% women) followed by Pakistanis. Bangladeshis also had the highest prevalence of hyperlipidaemia (23.6% men, 18.3% women), hypertension among women (24%), and incident tobacco use among men. Pakistani women had the highest prevalence of obesity (28%). For CHD, Bangladeshi men had the highest prevalence (7.3%), followed by Pakistanis (6.3%); and Pakistanis had the highest prevalence among women (3.2%). For HF, the prevalence in Pakistani and Bangladeshi women was more than twice that of locals. Indians had the lowest prevalence of diabetes across South Asians, and of CHD across South Asian men, while the prevalence of CHD among Indian women was twice that of local women (2.6% vs. 1.3%). Filipinos had the highest prevalence of hypertension among men (21.8%). Chinese men and women had the lowest prevalence of risk factors and CVD. CONCLUSIONS: In Catalonia, preventive interventions adapted to the risk profile of different Asian immigrant groups are needed, particularly for Bangladeshis and Pakistanis.

Socioeconomic Status and Distance to Reference Centers for Complex Cancer Diseases: A Source of Health Inequalities? A Population Cohort Study Based on Catalonia (Spain).

The centralization of complex surgical procedures for cancer in Catalonia may have led to geographical and socioeconomic inequities. In this population-based cohort study, we assessed the impacts of these two factors on 5-year survival and quality of care in patients undergoing surgery for rectal cancer (2011-12) and pancreatic cancer (2012-15) in public centers, adjusting for age, comorbidity, and tumor stage. We used data on the geographical distance between the patients' homes and their reference centers, clinical patient and treatment data, income category, and data from the patients' district hospitals. A composite 'textbook outcome' was created from five subindicators of hospitalization. We included 646 cases of pancreatic cancer (12 centers) and 1416 of rectal cancer (26 centers). Distance had no impact on survival for pancreatic cancer patients and was not related to worse survival in rectal cancer. Compared to patients with medium-high income, the risk of death was higher in low-income patients with pancreatic cancer (hazard ratio (HR) 1.46, 95% confidence interval (CI) 1.15-1.86) and very-low-income patients with rectal cancer (HR 5.14, 95% CI 3.51-7.52). Centralization was not associated with worse health outcomes in geographically dispersed patients, including for survival. However, income level remained a significant determinant of survival.

Development and validation of a population-based risk stratification model for severe COVID-19 in the general population.

The shortage of recently approved vaccines against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has highlighted the need for evidence-based tools to prioritize healthcare resources for people at higher risk of severe coronavirus disease (COVID-19). Although age has been identified as the most important risk factor (particularly for mortality), the contribution of underlying comorbidities is often assessed using a pre-defined list of chronic conditions. Furthermore, the count of individual risk factors has limited applicability to population-based "stratify-and-shield" strategies. We aimed to develop and validate a COVID-19 risk stratification system that allows allocating individuals of the general population into four mutually-exclusive risk categories based on multivariate models for severe COVID-19, a composite of hospital admission, transfer to intensive care unit (ICU), and mortality among the general population. The model was developed using clinical, hospital, and epidemiological data from all individuals among the entire population of Catalonia (North-East Spain; 7.5 million people) who experienced a COVID-19 event (i.e., hospitalization, ICU admission, or death due to COVID-19) between March 1 and September 15, 2020, and validated using an independent dataset of 218,329 individuals with COVID-19 confirmed by reverse transcription-polymerase chain reaction (RT-PCR), who were infected after developing the model. No exclusion criteria were defined. The final model included age, sex, a summary measure of the comorbidity burden, the socioeconomic status, and the presence of specific diagnoses potentially associated with severe COVID-19. The validation showed high discrimination capacity, with an area under the curve of the receiving operating characteristics of 0.85 (95% CI 0.85-0.85) for hospital admissions, 0.86 (0.86-0.97) for ICU transfers, and 0.96 (0.96-0.96) for deaths. Our results provide clinicians and policymakers with an evidence-based tool for prioritizing COVID-19 healthcare resources in other population groups aside from those with higher exposure to SARS-CoV-2 and frontline workers.

Frequency of health-care service use and severity of illness in undocumented migrants in Catalonia, Spain: a population-based, cross-sectional study.

BACKGROUND: In Spain, legislation was passed in 2012 excluding undocumented migrants from the public health-care system. Catalonia was one of the Spanish regions that did not implement this legislation, and continued to guarantee access to health care to the whole population. We aimed to analyse health-care use and health status among undocumented migrants in Catalonia, and compare health-care use and health status with legal residents classified according to their socioeconomic position (SEP). METHODS: We did a population-based, cross-sectional study, with administrative individual data. The study included the resident population in Catalonia, Spain, in 2017, aged younger than 65 years and with a maximum annual income of less than €18 000 per year, and classified into three socioeconomic (SEP) groups-low SEP, very low SEP, and undocumented migrants. Indicators regarding health-care service use (primary care, emergency care, mental health care, acute care), drug prescriptions, and selected chronic and infectious diseases were analysed. FINDINGS: Between Jan 1 and Dec 31, 2017, 4 071 988 residents of Catalonia were included in this study; undocumented migrants represented 2·8% (n=113 450) of this population. Of all undocumented migrants, 25 942 (61·0%) female participants aged 15-64 years and 19 819 (46·0%) male participants aged 15-64 years attended primary health-care centres: these rates were lower than in individuals with a very low SEP (84·8% in female participants and 72·1% in male participants). Hospital admission rates among male participants aged 15-64 years in the very low SEP group were more than three times as high as in undocumented migrants (111·6 vs 35·7). The highest tuberculosis rate was found in undocumented male migrants (incidence rate 4·35 [95% CI 3·55-5·16]). INTERPRETATION: Undocumented migrants made less use of health-care services than those in the low and very low SEP groups, but for some infectious diseases, incidence was higher in undocumented migrants. These results constitute an additional argument to support the maintenance of universal health coverage for all citizens. FUNDING: None.

Impact on clinical outcomes and health costs of deranged potassium levels in patients with chronic cardiovascular, metabolic, and renal conditions.

INTRODUCTION AND OBJECTIVES: Potassium derangements are frequent among patients with chronic cardiovascular conditions. Studies on the associations between potassium derangements and clinical outcomes have yielded mixed findings, and the implications for health care expenditure are unknown. We assessed the population-based associations between hyperkalemia, hypokalemia and clinical outcomes and health care costs, in patients with chronic heart failure, chronic kidney disease, diabetes mellitus, hypertension, and ischemic heart disease. METHODS: Population-based, longitudinal study including up to 36 269 patients from a health care area with at least one of the above-mentioned conditions. We used administrative, hospital and primary care databases. Participants were followed up between 2015 and 2017, were aged ≥ 55 years and had at least 1 potassium measurement. Four analytic designs were used to evaluate prevalent and incident cases and the use of renin-angiotensin-aldosterone system inhibitors. RESULTS: Hyperkalemia was twice as frequent as hypokalemia. On multivariable-adjusted analyses, hyperkalemia was robustly and significantly associated with an increased risk of all-cause death (HR from Cox regression models ranging from 1.31-1.68) and with an increased odds of a yearly health care expenditure >85th percentile (OR, 1.21-1.29). Associations were even stronger in hypokalemic patients (HR for all-cause death, 1.92-2.60; OR for health care expenditure> percentile 85th, 1.81-1.85). CONCLUSIONS: Experimental studies are needed to confirm whether the prevention of potassium derangements reduces mortality and health care expenditure in these chronic conditions. Until then, our findings provide observational evidence on the potential importance of maintaining normal potassium levels.

Performance of Three Measures of Comorbidity in Predicting Critical COVID-19: A Retrospective Analysis of 4607 Hospitalized Patients.

BACKGROUND: Comorbidity burden has been identified as a relevant predictor of critical illness in patients hospitalized with coronavirus disease 2019 (COVID-19). However, comorbidity burden is often represented by a simple count of few conditions that may not fully capture patients' complexity. PURPOSE: To evaluate the performance of a comprehensive index of the comorbidity burden (Queralt DxS), which includes all chronic conditions present on admission, as an adjustment variable in models for predicting critical illness in hospitalized COVID-19 patients and compare it with two broadly used measures of comorbidity. MATERIALS AND METHODS: We analyzed data from all COVID-19 hospitalizations reported in eight public hospitals in Catalonia (North-East Spain) between June 15 and December 8 2020. The primary outcome was a composite of critical illness that included the need for invasive mechanical ventilation, transfer to ICU, or in-hospital death. Predictors including age, sex, and comorbidities present on admission measured using three indices: the Charlson index, the Elixhauser index, and the Queralt DxS index for comorbidities on admission. The performance of different fitted models was compared using various indicators, including the area under the receiver operating characteristics curve (AUROCC). RESULTS: Our analysis included 4607 hospitalized COVID-19 patients. Of them, 1315 experienced critical illness. Comorbidities significantly contributed to predicting the outcome in all summary indices used. AUC (95% CI) for prediction of critical illness was 0.641 (0.624-0.660) for the Charlson index, 0.665 (0.645-0.681) for the Elixhauser index, and 0.787 (0.773-0.801) for the Queralt DxS index. Other metrics of model performance also showed Queralt DxS being consistently superior to the other indices. CONCLUSION: In our analysis, the ability of comorbidity indices to predict critical illness in hospitalized COVID-19 patients increased with their exhaustivity. The comprehensive Queralt DxS index may improve the accuracy of predictive models for resource allocation and clinical decision-making in the hospital setting.

Decline in hospitalisations due to dog bite injuries in Catalonia, 1997-2008. An effect of government regulation?

OBJECTIVE: To analyse population-based data on hospitalisation caused by dog bite injuries after changes in legal regulations on dog ownership, including breed-specific regulations. DESIGN: Descriptive study. SETTING: Hospitals in Catalonia (Spain), 1997-2008. SUBJECTS: Persons hospitalised with injuries caused by dog bites. RESULTS: There has been a significant decline in hospitalisation caused by injuries from dog bites from 1.80/100,000 in 1997-9 to 1.11/100,000 in 2006-8, after the enactment of stricter regulations on dog ownership in 1999 and 2002. The magnitude of this change is significant (-38%), and has been greatest in less urban settings. CONCLUSIONS: Government regulations were associated with a sizable decrease in injuries caused by dog bites in Catalonia. More evaluative studies in this field may provide criteria to focus future regulations and other preventive interventions.