Association of Healthcare Fragmentation and the Survival of Patients with Colorectal Cancer in Colombia.

OBJECTIVES: The objective of this study was to identify the association between healthcare fragmentation and survival for patients with colorectal cancer in Colombia. METHODS: A retrospective cohort study was performed using administrative databases, with an electronic algorithm to identify patients with colorectal cancer based on codes. The patients were enrolled between January 1, 2013, and December 31, 2016. The exposure variable was fragmentation, which was measured based on the number of different healthcare institutions that treated a patient during the first year after diagnosis. Matching was performed using propensity scores to control for confounding, and the hazard ratio for exposure to higher fragmentation was calculated for the matched sample. RESULTS: A total of 5036 patients with colorectal cancer were identified, 2525 (49.88%) of whom were women. The mean number of network healthcare institutions for the total sample was 5.71 (SD 1.98). The patients in the quartile with higher fragmentation had the highest mortality rate, 35.67 (95% CI 33.63-38.06) per 100 patients. The comparison of higher and lower quartiles of fragmentation resulted in an incidence rate ratio of 1.23 (95% CI 1.04-1.45; P = .02). Of the 5036 patients, 422 (8.38%) were classified as the exposed cohort (higher fragmentation). The total matched sample consisted of 844 subjects, and an HR of 1.26 (95%CI; 1.05-1.51) was estimated. CONCLUSIONS: Exposure to more highly fragmented healthcare networks decreases overall 4-year survival for patients with colorectal cancer in Colombia.

Cost-Effectiveness of Comprehensive Genomic Profiling in Patients With Non-Small Cell Lung Cancer for the Colombian Health System.

INTRODUCTION: The use of comprehensive genomic profiling (CGP) and target therapies is associated with substantial improvements in clinical outcomes among patients with non-small cell lung cancer (NSCLC). However, the costs of CGP may increase the financial pressures of NSCLC on health systems worldwide, especially in low- and middle-income countries. This study aimed to estimate the cost-effectiveness of CGP compared with current genomic tests in patients with NSCLC from the perspective of the Colombian Health System. METHODS: To estimate the costs and benefits of CGP and its comparators, we developed a 2-stage cohort model with a lifetime horizon. In the first stage, we made up a decision tree that calculated the probability of receiving each therapy as result of identifying a specific, actionable target. In the second stage, we developed a partitioned survival model that estimated the time spent at each health state. Incremental cost-effectiveness ratios were calculated for life-years (LYs) and quality-adjusted LYs gained. All costs were expressed in 2019 international dollars (INT$). RESULTS: CGP is associated with gains of 0.06 LYs and 0.04 quality-adjusted LYs compared with current genomic tests. Incremental cost-effectiveness ratios for CGP ranged from INT$861 to INT$7848, depending on the outcome and the comparator. Sensitivity analyses show that the cost-effectiveness decision was sensitive to prices of CGP above INT$7170 per test. These results are robust to most deterministic and probabilistic sensitivity analyses. CONCLUSIONS: CGP may be cost-effective in patients with NSCLC from the perspective of the Colombian Health System (societal willingness-to-pay threshold of INT$15 630 to INT$46 890).

Teaching hospitals and their influence on survival after valve replacement procedures: A retrospective cohort study using inverse probability of treatment weighting (IPTW).

BACKGROUND: The effect of teaching hospital status on cardiovascular surgery has been of common interest in recent decades, yet its magnitude on heart valve replacement is still a matter of debate. Given the ethical and practical unfeasibility of randomly assigning a patient to such an exposure, we use the inverse probability of treatment weighting (IPTW) to assess this marginal effect on the survival of Colombian patients who underwent a first heart valve replacement between 2016 and 2019. METHODS: A retrospective cohort study was conducted based on administrative records. The time-to-death event and cumulative incidences of death, readmission, and reoperation are presented as outcomes. An artificial sample is configured through IPTW, adjusting for sociodemographic variables, comorbidities, technique, and intervention weight. RESULTS: Of a sample of 3,517 patients, 1,051 (29.9%) were operated on in a teaching hospital. The median age was 65.0 (18.1-91.5), 38.5% of patients were ≤60, and 6.9% were ≥80. The cumulative incidences of death at 30, 90 days, and one year were 5.9%, 8%, and 10.9%, respectively. Furthermore, 23.5% of the patients were readmitted within 90 days and 3.6% underwent reintervention within one year. The odds of 30-day mortality are lower for patients operated in a teaching hospital (OR 0.51; 95% CI 0.29-0.92); however, no effect on survival was identified in terms of time-to-event of death (HR 1.07; 95%CI 0.78-1.46). CONCLUSIONS: After IPTW, the odds of 30-day mortality are lower for patients operated in a teaching hospital. There was no effect on survival, 90-day or one-year mortality, 90-day readmission, or one-year reintervention. Together, we offer an opening for investigating an exposure that has yet to be explored in Latin America with potential value to understand teaching hospitals as the essential nature of reality of an academic-clinical synergy.

HOSPITAL VOLUME, POSTOPERATIVE MORTALITY, AND COSTS AFTER GASTRECTOMY FOR GASTRIC CANCER IN COLOMBIA: IS THERE ANY ASSOCIATION?

BACKGROUND: There are no information in the literature associating the volume of gastrectomies with survival and costs for the health system in the treatment of patients with gastric cancer in Colombia. AIMS: The aim of this study was to analyze how gastrectomy for gastric cancer is associated with hospital volume, 30-day and 180-day postoperative mortality, and healthcare costs in Bogotá, Colombia. METHODS: A retrospective cohort study based on hospital data of all adult patients with gastric cancer who underwent gastrectomy between 2014 and 2016 using a paired propensity score. The surgical volume was identified as the average annual number of gastrectomies performed by the hospital. RESULTS: A total of 743 patients were included in the study. Hospital mortality at 30 and 180 days postoperatively was 36 (4.85%) and 127 (17.09%) patients, respectively. The average health care cost was USD 3,200. A total of 26 or more surgeries were determined to be the high surgical volume cutoff. Patients operated on in hospitals with a high surgical volume had lower 6-month mortality (HR 0.44; 95%CI 0.27-0.71; p=0.001), and no differences were found in health costs (mean difference 398.38; 95%CI-418.93-1,215.69; p=0.339). CONCLUSIONS: This study concluded that in Bogotá (Colombia), surgery in a high-volume hospital is associated with better 6-month survival and no additional costs to the health system.

Changes in birth outcomes and utilization of prenatal care during the COVID-19 pandemic in 2020: a secondary analysis of vital statistics in Colombia.

BACKGROUND: Birth outcomes could have been affected by the COVID-19 pandemic through changes in access to prenatal services and other pathways. The aim of this study was to examine the effects of the COVID-19 pandemic on fetal death, birth weight, gestational age, number of prenatal visits, and caesarean delivery in 2020 in Colombia. METHODS: We conducted a secondary analysis of data on 3,140,010 pregnancies and 2,993,534 live births from population-based birth certificate and fetal death certificate records in Colombia between 2016 and 2020. Outcomes were compared separately for each month during 2020 with the same month in 2019 and pre-pandemic trends were examined in regression models controlling for maternal age, educational level, marital status, type of health insurance, place of residence (urban/rural), municipality of birth, and the number of pregnancies the mother has had before last pregnancy. RESULTS: We found some evidence for a decline in miscarriage risk in some months after the pandemic start, while there was an apparent lagging increase in stillbirth risk, although not statistically significant after correction for multiple comparisons. Birth weight increased during the onset of the pandemic, a change that does not appear to be driven by pre-pandemic trends. Specifically, mean birth weight was higher in 2020 than 2019 for births in April through December by about 12 to 21 g (p < 0.01). There was also a lower risk of gestational age at/below 37 weeks in 2020 for two months following the pandemic (April, June), but a higher risk in October. Finally, there was a decline in prenatal visits in 2020 especially in June-October, but no evidence of a change in C-section delivery. CONCLUSIONS: The study findings suggest mixed early effects of the pandemic on perinatal outcomes and prenatal care utilization in Colombia. While there was a significant decline in prenatal visits, other factors may have had counter effects on perinatal health including an increase in birth weight on average.

Fragmentation of Care and Its Association With Survival and Costs for Patients With Breast Cancer in Colombia.

PURPOSE: Breast cancer care requires a multimodal approach and a multidisciplinary team who must work together to obtain good clinical results. The fragmentation of care can affect the breast cancer care; however, it has not been measured in a low-resource setting. The aim of this study was to identify fragmentation of care, the geographic variation of this and its association with 4-year overall survival (OS), and costs of care for patients with breast cancer enrolled in Colombia's contributory health care system. MATERIALS AND METHODS: A retrospective cohort study was conducted using administrative databases. Women with breast cancer who were treated from January 1, 2013, to December 31, 2015, were included. Fragmentation of care was the exposure, which was measured by the number of different health care provider institutions (HCPIs) that treated a patient during the first year after diagnosis. Crude mortality rates were estimated, survival functions were calculated using the nonparametric Kaplan-Meier approach, and adjusted hazard ratios (HRs) were estimated using multivariate Cox regression model to identify the association of fragmentation with 4-year OS. The association between fragmentation and costs of care was assessed using a multivariate linear regression model. RESULTS: A total of 10,999 patients with breast cancer were identified, and 1,332 deaths were observed. The 4-year crude mortality rate was 31.97 (95% CI, 30.25 to 33.69) per 1,000 person-years for the whole cohort, and the highest rate was in the cohort defined for the fourth quartile of the fragmentation measurement (eight or more HCPIs), 40.94 (95% CI, 36.49 to 45.39). The adjusted HR for 4-year OS was 1.04 (95% CI, 1.01 to 1.07) for each HCPI additional. The cost of care is increased for each additional HCPIs (cost ratio, 1.25; 95% CI, 1.23 to 1.26). CONCLUSION: Fragmentation of care decreases overall 4-year OS and increases the costs of care in women with breast cancer for Colombia.

Effect of bloodstream infection on survival in COVID-19 patients admitted to an intensive care unit in Colombia: a matched cohort analysis.

Aim: To determine the impact of bloodstream infection (BSI) and other risk factors for mortality in patients with COVID-19 admitted to the intensive care unit (ICU). Methods: A retrospective cohort was carried out at the Hospital Universitario Nacional (HUN) between March 29 and December 19, 2020. Patients with COVID-19 admitted to the Intensive Care Unit (ICU) were paired 1:4 in two groups, one with BSI and the other without, according to hospital stay and the month of admission. The primary outcome was mortality at 28 days. A Cox proportional hazards model was used to estimate differences in mortality risk. Results: 456 patients were identified and 320 were included in the final cohort, 18% (n = 59) in the BSI group and 82% (n = 261) in the control group. 125 (39%) patients died, 30 (51%) in the BSI group and 95 (36%) in the control group (P = 0.040). BSI was associated with an increased risk of in-hospital mortality at 28 days, [HR] 1.77 (95% CI: 1.03-3.02; P = 0.037). Invasive mechanical ventilation (IMV) and age were associated with increased mortality risk. Some months of the year of the hospital stay were associated with a reduced risk of mortality. There was no difference in mortality between inappropriate and appropriate empirical antimicrobial use. Conclusion: BSI in patients with COVID-19 in ICU increases in-hospital mortality to 28 days. Other risk factors for mortality were IMV and age.

Prevalence of lung cancer in Colombia and a new diagnostic algorithm using health administrative databases: A real-world evidence study.

Reliable, timely and detailed information on lung cancer prevalence, mortality and costs from middle-income countries is essential to policy design. Thus, we aimed to develop an electronic algorithm to identify lung cancer prevalent patients in Colombia by using administrative claims databases, as well as to estimate prevalence rates by age, sex and geographic region. We performed a cross-sectional study based on national claim databases in Colombia (Base de datos de suficiencia de la Unidad de Pago por Capitación and Base de Datos Única de Afiliados) to identify lung cancer prevalent patients in 2017, 2018 and 2019. Several algorithms based on the presence or absence of oncological procedures (chemotherapy, radiotherapy and surgery) and a minimum number of months that each individual had lung cancer ICD-10 codes were developed. After testing 16 algorithms, those with the closest prevalence rates to those rates reported by aggregated official sources (Global Cancer Observatory and Cuenta de Alto Costo) were selected. We estimated prevalence rates by age, sex and geographic region. Two algorithms were selected: i) one algorithm that was defined as the presence of ICD-10 codes for 4 months or more (the sensitive algorithm); and ii) one algorithm that was defined by adding the presence of at least one oncological procedure (the specific algorithm). The estimated prevalence rates per 100,000 inhabitants ranged between 11.14 and 18.05 for both, the contributory and subsidized regimes over years 2017, 2018 and 2019. These rates in the contributory regime were higher in women (15.43, 15.61 and 17.03 per 100,000 for years 2017, 2018 and 2019), over 65-years-old (63.45, 56.92 and 61.79 per 100,000 for years 2017, 2018 and 2019) who lived in Central, Bogota and Pacific regions. Selected algorithms showed similar aggregated prevalence estimations to those rates reported by official sources and allowed us to estimate prevalence rates in specific aging, regional and gender groups for Colombia by using national claims databases. These findings could be useful to identify clinical and economical outcomes related to lung cancer patients by using national individual-level databases.

Failure to Rescue and Mortality Differences After Appendectomy in a Low-Middle-Income Country and the United States.

BACKGROUND: Major disparities in complications and mortality after appendectomy between countries with different income levels have not been well characterized, as comparative studies at patient level between countries are scant. This study aimed to investigate variations in postoperative complications, mortality, and failure to rescue after appendectomy between a high-income country and a low-to-middle-income country. METHODS: Hospital discharges on adult patients who underwent appendectomy were extracted from administrative databases from Colombia and 2 states of the United States (Florida and New York). Outcomes included major postoperative complications, in-hospital mortality, and failure to rescue. Univariate analyses were conducted to compare outcomes between the 2 countries. Multivariable logistic regression analyses were conducted to examine the independent effect of country on outcomes after adjustment for patient age, sex, comorbidity index, severity of appendicitis, and appendectomy route (laparoscopic/open). RESULTS: A total of 62,338 cases from Colombia and 57,987 from the United States were included in the analysis. Patients in Colombia were significantly younger and healthier but had a higher incidence of peritonitis. Use of laparoscopy was significantly lower in Colombia (5.9% vs 89.4%; P < .0001). After adjustment for covariates, multivariable logistic regression analyses revealed that compared to the United States, Colombia had lower complication rates (2.8% vs 6.6%; odds ratio [OR], 0.41; 95% confidence interval [CI], 0.39-0.44; P < .0001) but higher mortality (0.44% vs 0.08%; OR, 8.92; 95% CI, 5.69-13.98; P < .0001) and failure to rescue (13.6% vs 1.0%; OR, 17.01; 95% CI, 10.66-27.16; P < .0001). CONCLUSIONS: Despite lower rates of postoperative complications, in-hospital mortality after appendectomy was higher in Colombia than in the United States. This difference may be explained by higher rates of failure to rescue in the low-to-middle-income country (ie, decreased ability of Colombian hospitals to rescue patients from complications).

Three-Dimensional Orientation of the Native Anterior Cruciate Ligament in Magnetic Resonance Imaging.

The aim of this study was to describe the three-dimensional orientation of the native anterior cruciate ligament (ACL) in magnetic resonance imaging (MRI) by calculating the angles of inclination in relation to the axial plane which is given for the knee joint line in a group of healthy individuals. These could help to establish guidelines that may be used for the surgical positioning of bone tunnels during ACL reconstruction. A total of 290 MRI scans of patients with integrity of the ACL were evaluated; three observers identified the coordinates of the femoral and tibial insertion sites, then it is defined the vector and evaluated its angles with respect to axial axis and calculated the angles with trigonometric equations. The data were analyzed according to the age, sex, side, BMI, and height of the patients, and the interobserver reliability was calculated. The patient demographics were as follows: age average: 45 years old, BMI average: 27.1, 54% right knees, and 60% female. The average angle for all the measurements was 76.95 degrees (SD ± 6.8 degrees) in the sagittal plane, 81.65 degrees (SD ± 7.79 degrees) in the coronal plane and 33.17 degrees (SD ± 4.98 degrees) in the axial plane. No statistically significant differences were found between the categorical variables mentioned; moderate to substantial interobserver reliability strength was found with an average kappa of 0.791 for all measurements. The three-dimensional orientation of the native ACL in a group of healthy individuals was established. The findings can be helpful for performing anatomical reconstructions of the ACL in injured patients using as reference the average calculated angles, or measure of the contralateral non-injured knee for surgical planning; these results serve as a basis for the design of a technique that optimizes the three-dimensional position of the ACL when it undergoes reconstruction in the trend toward greater precision for better functional results. Biomechanical and clinical-surgical studies are required to further evaluate our results.

Hospital volume, postoperative mortality, and costs after gastrectomy for gastric cancer in colombia: is there any association? / Volume hospitalar, mortalidade pós-operatória e custos após gastrectomia por câncer gástrico na colômbia: existe associação?

ABSTRACT BACKGROUND: There are no information in the literature associating the volume of gastrectomies with survival and costs for the health system in the treatment of patients with gastric cancer in Colombia. AIMS: The aim of this study was to analyze how gastrectomy for gastric cancer is associated with hospital volume, 30-day and 180-day postoperative mortality, and healthcare costs in Bogotá, Colombia. METHODS: A retrospective cohort study based on hospital data of all adult patients with gastric cancer who underwent gastrectomy between 2014 and 2016 using a paired propensity score. The surgical volume was identified as the average annual number of gastrectomies performed by the hospital. RESULTS: A total of 743 patients were included in the study. Hospital mortality at 30 and 180 days postoperatively was 36 (4.85%) and 127 (17.09%) patients, respectively. The average health care cost was USD 3,200. A total of 26 or more surgeries were determined to be the high surgical volume cutoff. Patients operated on in hospitals with a high surgical volume had lower 6-month mortality (HR 0.44; 95%CI 0.27-0.71; p=0.001), and no differences were found in health costs (mean difference 398.38; 95%CI-418.93-1,215.69; p=0.339). CONCLUSIONS: This study concluded that in Bogotá (Colombia), surgery in a high-volume hospital is associated with better 6-month survival and no additional costs to the health system.

RESUMO RACIONAL: Não há informações na literatura relacionando o volume de gastrectomias bem como a sobrevida e os custos para o sistema de saúde, no tratamento de pacientes com câncer gástrico na Colômbia. OBJETIVOS: analisar como a gastrectomia para câncer gástrico está associada ao volume hospitalar, mortalidade pós-operatória de 30 e 180 dias e custos de saúde em Bogotá, Colômbia. MÉTODOS: Estudo de coorte retrospectivo baseado em dados hospitalares de todos os pacientes adultos com câncer gástrico submetidos à gastrectomia entre 2014 e 2016, utilizando um escore de propensão pareado. O volume cirúrgico foi identificado como o número médio anual de gastrectomias realizadas pelo hospital. RESULTADOS: Foram incluídos no estudo 743 pacientes. A mortalidade hospitalar aos 30 e 180 dias de pós-operatório, foram respectivamente, 36 (4,85%) e 127 (17,09%) pacientes. O custo médio de saúde foi de US$ 3.200. Vinte e seis ou mais cirurgias foram determinadas como ponto de corte de alto volume cirúrgico. Pacientes operados em hospitais de alto volume cirúrgico tiveram menor mortalidade em seis meses (HR 0,44; IC95% 0,27-0,71; p=0,001) e não foram encontradas diferenças nos custos com saúde (diferença média 398,38; IC95% −418,93-1215,69; p=0,339). CONCLUSÕES: Este estudo concluiu que em Bogotá (Colômbia), a cirurgia em um hospital com alto volume cirúrgico está associada a uma melhor sobrevida de seis meses e não há custos adicionais para o sistema de saúde.

Acute Kidney Injury in a Cohort of Critical Illness Patients Exposed to Non-Steroidal Anti-Inflammatory Drugs.

To determine whether non-steroidal anti-inflammatory drug (NSAIDs) exposure prior to intensive care unit (ICU) admission affects the development of acute kidney injury (AKI) with renal replacement therapy (RRT). An administrative database is used to establish a cohort of patients who were admitted to the ICU. The exposure to NSAIDs that the patients had before admission to the ICU is determined. Demographic variables, comorbidities, AKI diagnoses requiring RRT, and pneumonia during the ICU stay are also measured. Multivariate logistic regression and inverse probability weighting (IPW) are used to calculate risks of exposure to NSAIDs for patients with AKI requiring RRT. In total, 96,235 patients were admitted to the ICU, of which 16,068 (16.7%) were exposed to NSAIDs. The incidence of AKI with RRT was 2.71% for being exposed to NSAIDs versus 2.24% for those not exposed (p < 0.001). For the outcome of AKI, the odds ratio weighted with IPW was 1.28 (95% CI: 1.15−1.43), and for the outcome of pneumonia as a negative control, the odds ratio was 1.07 (95% CI: 0.98−1.17). The impact of prior exposure to NSAIDs over critically ill patients in the development of AKI is calculated as 8 patients per 1000 exposures. The negative control with the same sources of bias did not show an association with NSAID exposure.

Medium Cutoff Versus High-Flux Hemodialysis Membranes and Clinical Outcomes: A Cohort Study Using Inverse Probability Treatment Weighting.

Rationale & Objective: This study investigated the effects on patients' outcomes of using medium cutoff (MCO) versus high-flux (HF) dialysis membranes. Study Design: A retrospective, observational, multicenter, cohort study. Setting & Participants: Patients aged greater than 18 years receiving hemodialysis at the Baxter Renal Care Services dialysis network in Colombia. The inception of the cohort occurred from September 1, 2017, to November 30, 2017, with follow-up to November 30, 2019. Exposure: The patients were divided into 2 cohorts according to the dialyzer used at the inception: (1) MCO membrane or (2) HF membrane. Outcomes: Primary outcomes were the hospitalization rate from any cause and hospitalization days per patient-year. Secondary outcomes were acute cardiovascular events and mortality rates from any cause and secondary to cardiovascular causes. Laboratory parameters were assessed throughout the 2-year follow-up period. Analytical Approach: Descriptive statistics were used to report population characteristics. Inverse probability of treatment weighting was applied to each group before analysis. All categorical variables were compared using Pearson's χ2 test, and continuous variables were analyzed with the t test. Baseline differences between groups with a value of >10% were considered clinically meaningful. Laboratory variables were measured at 5 consecutive time points. A between-patient effect was analyzed using a split-plot factorial analysis of variance. Results: The analysis included 1,098 patients, of whom 564 (51.3%) were dialyzed with MCO membranes and 534 (48.7%) with HF membranes. Patients receiving hemodialysis with MCO membranes had a lower all-cause hospitalization incidence rate (IR) per patient-year (IR = 0.93; 95% CI, 0.82-1.03) than those receiving hemodialysis with HF membranes (IR = 1.13; 95% CI, 0.96-1.30), corresponding to a significant incident rate ratio (MCO/HF) of 0.82 (95% CI, 0.68-0.99; P = 0.04). The frequency of nonfatal cardiovascular events showed statistical significance, with a lower incidence in the MCO group (incident rate ratio = 0.66; 95% CI, 0.46-0.96; P = 0.03). No statistically significant differences in all-cause time until death were observed (P = 0.48). Albumin levels were similar between the 2 dialyzer cohorts. Limitations: Despite the robust statistical analysis, there remains the possibility that unmeasured variables may still generate residual imbalance and, therefore, skew the results. Conclusions: The incidences of hospitalization and cardiovascular events in patients receiving hemodialysis were lower when dialyzed with MCO membranes than HF membranes. A randomized controlled trial would be desirable to confirm these results. Trial Registration: Clinical Trials.gov, ISRCTN12403265.

Prognostic Factors of Clinical and Economic Outcomes of Hip Arthroplasty in a Developing Country: A Multilevel Analysis with a 4-Year Cohort Study.

Introduction: This study is aimed at estimating the 30-day postoperative mortality rate and total costs of the medical episode, as well as determining prognostic factors associated with these outcomes for adult patients who have undergone total hip arthroplasty (THA) in Colombia's contributory health system. Methods: This was a retrospective cohort using administrative data and included adult patients enrolled in Colombia's contributory health system who underwent THA between the years 2011 and 2014. Outcomes were 30-day mortality ICU admissions, and the 1-year rate of fractures and revisions as well as the total cost of the medical episode incurred by the third-payer for 90 days following the procedure. Multilevel linear regression models were also generated to determine the prognostic factors associated with the outcomes presented. Results: The study included 17,289 patients, with an average age of 67 years. Outcome rates were calculated per 100 surgeries, resulting in 2.15 for mortality, 3.41 for ICU admissions, 2.42 for revision hip arthroplasty and 0.62 for periprosthetic fractures. This study found the age and Charlson Comorbidity Index were associated with mortality and complications, and that being female and performing the procedure in the capital city were protective factors. It also found that the median total cost of the medical episode was USD $ USD$2742.161 (p25-p75: 353.092-3291.747). The multivariate model found increasing trends in cost as age and CCI scores rose, and higher costs in the Atlantic region. Conclusions: Colombia has higher rates of complications from THA than other countries but lower health system costs. For these patients, age, CCI and the geographic region are factors that are associated with mortality, complications, and health system costs.

Understanding how socioeconomic inequalities drive inequalities in COVID-19 infections.

Across the world, the COVID-19 pandemic has disproportionately affected economically disadvantaged groups. This differential impact has numerous possible explanations, each with significantly different policy implications. We examine, for the first time in a low- or middle-income country, which mechanisms best explain the disproportionate impact of the virus on the poor. Combining an epidemiological model with rich data from Bogotá, Colombia, we show that total infections and inequalities in infections are largely driven by inequalities in the ability to work remotely and in within-home secondary attack rates. Inequalities in isolation behavior are less important but non-negligible, while access to testing and contract-tracing plays practically no role because it is too slow to contain the virus. Interventions that mitigate transmission are often more effective when targeted on socioeconomically disadvantaged groups.

Validation and adaptation of the Charlson Comorbidity Index using administrative data from the Colombian health system: retrospective cohort study.

OBJECTIVE: To validate the Charlson Comorbidity Index (CCI) for the Colombian population using administrative databases from the health insurance system. DESIGN: Retrospective cohort study. SETTING: Database reports of events related to services that insurers provided (Health Promoter Enterprises, EPS in Spanish) in the Colombian health system, which covered 22.19 million residents in 2016. PARTICIPANTS: The study cohort comprised 3 849 849 patients aged 18 years and up admitted to the Colombian hospitals between 1 January and 31 December 2016. PRIMARY OUTCOME: The study aimed to gauge the CCI's predictive value for mortality by comparing the calibration and discrimination of three different versions of the index, with mortality information obtained from death certificates, including date of death and diagnoses associated with cause of death. Follow-up was conducted for at least 1 year. RESULTS: Altogether, 46 429 patients died within 1 year (1.21%). Discriminatory power in predicting 1-year mortality was calculated for three versions of the ICC. In the original CCI model, the area under the Receiver operating characteristic (ROC) curve was 0.906 (95% CI (0.906 to 0.907), p<0.001). In the version for Colombia, it was 0.908 (95% CI (0.908 to 0.909), p<0.001) and for the new model it was 0.909 (95% CI (0.908 to 0.910), p<0.001). CONCLUSIONS: Adapting the CCI based on the 14 predictive variables of the new model resulted in an adequate predictive value for 1-year mortality in patients who were hospitalised for all causes. These findings support the use of the modified CCI in the Colombian population.

Attributable Costs of Lung Cancer for the Colombian Health System: A Cost-of-Illness Study.

OBJECTIVES: Lung cancer imposes a significant economic burden on most countries. Nevertheless, there is scarce information about this burden on health systems in low- and middle-income countries. This study aims to estimate the economic burden of lung cancer on the Colombian health system, a middle-income country with universal health coverage in Latin America. METHODS: We conducted a cost-of-illness study that included all direct costs generated by prevalent cases of lung cancer in Colombia during 2017. We used administrative databases containing patient-level information on consumption of healthcare services and reports on healthcare spending published by the Colombian Ministry of Health. To decrease the probability of misallocation of costs, we used propensity score matching to estimate the marginal costs of delivering healthcare services to patients with lung cancer. Additionally, ordinary least squares and variations in case definitions were used to assess the robustness of all estimates. RESULTS: Total costs attributable to lung cancer in 2017 ranged from $50 039 588 to $74 468 111, with important differences across insurance regimes (from $4 629 938 for the subsidized regime to $55 342 357 for the contributory regime). Notably, 43% of all costs ($27 081 348) were caused by the consumption of services not included in the health benefit package. There were no significant differences between inpatient and outpatient costs. CONCLUSIONS: Lung cancer imposes a significant economic burden on the Colombian health system. Although all affiliates are entitled to a unique health benefit package, there were important differences in costs across insurance regimes. Further research is needed to identify the main mechanisms underlying these differences.

SARS-CoV-2 Drive/Walk-Thru screening centers in Colombia: The CoVIDA Project / Centros de tamizaje masivo para SARS COV-2 en Colombia: Proyecto CoVIDA

Abstract Objective: The CoVIDA project is a public-private collaboration led by Universidad de los Andes that contributed to the SARS-CoV-2 epidemiological surveillance in Bogotá and nearby municipalities. We aimed to describe the development and performance of the Drive/Walk-through free RT- PCR for SARS-CoV-2 testing strategy implemented by CoVIDA. Material and method: We performed a descriptive analysis of the characteristics and performance of the CoVIDA Drive/Walk-through testing centers. The model and the process indicators to assess the model's performance were based on international experiences and scientific literature. Two screening centers were imple mented in shopping centers in the north and south of Bogotá. We reported the number of tests taken, the number of positive tests, and the number of participants that used the model by the type of occupations. Results: In total, 36,689 nasopharyngeal RT-PCR tests for SARS-CoV-2 were performed with a 5.75% cumulative positivity. Process indicators showed an excellent performance and an important contribution in reducing barriers to access to testing. Conclusions: the CoVIDA Drive/Walk-through testing centers supported the epidemiological surveillance in asymptomatic or mild-symptomatic population in Bo gotá. Low and middle-income countries can use this model as a cost-effective and innovative solution strategy to intensify testing and help mitigate the pandemic.

Resumen Objetivo: El proyecto CoVIDA es una colaboración público-privada liderada por la Universidad de los Andes que contribuyó a la vigilancia epidemiológica del SARS-CoV-2 en Bogotá y municipios cercanos. Nuestro objetivo fue describir el desarrollo y rendimiento de la estrategia de tamizaje gratuito con RT-PCR mediante un modelo Drive/Walk through para SARS-CoV-2 implementado por CoVIDA. Materiales y métodos: Realizamos un análisis descriptivo de las características y desempeño de los centros de tamizaje Drive/Walk through de CoVIDA. El modelo y los indicadores de proceso para evaluar el desempeño del modelo se basaron en experiencias internacionales y la literatura científica. Se implementaron dos cen tros de tamizaje en centros comerciales del norte y sur de Bogotá. Se reportó la cantidad de pruebas tomadas, pruebas positivas y de participantes que utilizaron el modelo de acuerdo con el tipo de ocupaciones. Resultados : En total, se realizaron 36,689 pruebas RT-PCR nasofaríngeas para SARS-CoV-2 con una positividad acumulada del 5,75%. Los indicadores de proceso mostraron un excelente desempeño y una contribución importante en la reducción de las barreras de acceso a las pruebas. Conclusiones: los centros de tamizaje con modelo Drive/Walk through de CoVIDA apoyaron la vigilancia epidemiológica en población asintomática o con síntomas leves en Bogotá. Los países de ingresos bajos y medianos pueden utilizar este modelo como una estrategia innovadora y rentable para aumentar la realización de las pruebas y ayudar a mitigar la pandemia.

Presurgical time and associated factors as predictors of acute perforated appendicitis: a prospective cohort study in a teaching pediatric hospital in Colombia.

BACKGROUND: We aim to determine the association between out and in-hospital factors with time, from the beginning of the symptoms to the surgery, in patients with acute appendicitis treated at Fundación Hospital Pediatrico La Misericordia (HOMI) in Colombia. METHODS: Eleven month prospective cohort study of pediatric patients at HOMI with acute appendicitis diagnosis taken to surgery. Data from the out-of-hospital phase was collected by surveying parents, and the data regarding the in-hospital phase was completed with medical records. We analyzed the association between the time from the beginning of the symptoms to the surgery, and out and in-hospital factors associated with this time using generalized linear models. RESULTS: Eight hundred three patients were included in the study. Total pre-surgical time was longer in perforated appendicitis (PA) group (2.65 days, standard deviation (SD) 1.88 vs. 2.04 days, SD 1.45) (p < 0.01). Factors associated with longer total and out-of-hospital presurgical times were age under 4 years old, lower socioeconomic status, father as a caregiver, self-medication, and underestimating disease severity. CONCLUSIONS: Out-of-hospital timing determines the longer pre-surgical time in complicated appendicitis. Younger age and lower socioeconomic status affect time significantly. We suggest the implementation of strategies in order to lower prehospital time, rates, and costs of complicated appendicitis.