Association of Mortality and Charlson Comorbidity Index in Surgical Spinal Trauma Patients at a Level I Academic Center

OBJECTIVES

The Charlson Comorbidity Index score (CCI) records the presence of comorbidities with various weights for a total score to estimate mortality within 1 year of hospital admission. Our study sought to assess the association of CCI with mortality rates of patients undergoing surgical intervention.

STUDY DESIGN

Retrospective study.

METHODS

Retrospective study of patients with surgical spinal trauma at a large academic level I trauma tertiary center from 2015 to 2018. Information collected included age, sex, American Society of Anesthesiologists physical status, body mass index, Charlson comorbidities, injury severity score, the presence of spinal cord injury, and mortality. Mortality was measured at 30 days, 90 days, and 1 year. Descriptive and bivariate analyses were completed. The results were significant at P < 0.05.

RESULTS

The highest proportion of 1-year mortality was in the patients with cervical (11.3%) and thoracolumbar injuries (7.4%) (P = 0.002). Patients with low CCI had low 1-year mortality (1.7%). Patients with high CCI had high 1-year mortality (13.8%) (P < 0.001). A significant association existed between CCI and mortality at 30 days, 90 days, and 1 year (P < 0.001). Mortality was higher in patients with spinal cord injury (14/108; 13%) than in those without (11/232; 5%) (P = 0.021). No association existed between ISS and mortality (P = 0.26).

DISCUSSION

The CCI was associated with a higher proportion of deaths at 30 days, 90 days, and 1 year. This association may help predict this unfortunate complication and guide the surgical team in formulating treatment plans and counseling patients and families regarding mortality associated with these injuries and the risks of surgical intervention.

Increased insulin resistance in intensive care: longitudinal retrospective analysis of glycaemic control patients in a New Zealand ICU

BACKGROUND

Critical care populations experience demographic shifts in response to trends in population and healthcare, with increasing severity and/or complexity of illness a common observation worldwide. Inflammation in critical illness impacts glucose-insulin metabolism, and hyperglycaemia is associated with mortality and morbidity. This study examines longitudinal trends in insulin sensitivity across almost a decade of glycaemic control in a single unit.

METHODS

A clinically validated model of glucose-insulin dynamics is used to assess hour-hour insulin sensitivity over the first 72 h of insulin therapy. Insulin sensitivity and its hour-hour percent variability are examined over 8 calendar years alongside severity scores and diagnostics.

RESULTS

Insulin sensitivity was found to decrease by 50-55% from 2011 to 2015, and remain low from 2015 to 2018, with no concomitant trends in age, severity scores or risk of death, or diagnostic category. Insulin sensitivity variability was found to remain largely unchanged year to year and was clinically equivalent (95% confidence interval) at the median and interquartile range. Insulin resistance was associated with greater incidence of high insulin doses in the effect saturation range (6-8 U/h), with the 75th percentile of hourly insulin doses rising from 4-4.5 U/h in 2011-2014 to 6 U/h in 2015-2018.

CONCLUSIONS

Increasing insulin resistance was observed alongside no change in insulin sensitivity variability, implying greater insulin needs but equivalent (variability) challenge to glycaemic control. Increasing insulin resistance may imply greater inflammation and severity of illness not captured by existing severity scores. Insulin resistance reduces glucose tolerance, and can cause greater incidence of insulin saturation and resultant hyperglycaemia. Overall, these results have significant clinical implications for glycaemic control and nutrition management.

An international comparison of the cost of fluid resuscitation therapies

OBJECTIVE

Fluid resuscitation is a ubiquitous intervention in the management of patients treated in the intensive care unit, which has implications for intensive care unit resourcing and budgets. Our objective was to calculate the relative cost of resuscitation fluids in several countries to inform future economic evaluations.

METHODS

We collected site-level data regarding the availability and cost of fluids as part of an international survey. We normalised costs to net present values using purchasing power parities and published inflation figures. Costs were also adjusted for equi-effective dosing based on intravascular volume expansion effectiveness and expressed as US dollars (USD) per 100 mL crystalloid equivalent.

RESULTS

A total of 187 sites had access to cost data. Between countries, there was an approximate six fold variation in the cost of crystalloids and colloids overall. The average cost for crystalloids overall was less than 1 USD per 100 mL. In contrast, colloid fluids had higher average costs (59 USD per 100 mL). After adjusting for equi-effective dosing, saline was ∼27 times less costly than albumin (saline: 0.6 USD per 100 mL crystalloid equivalent; albumin 4-5%: 16.4 USD; albumin 20-25%: 15.8 USD) and ∼4 times less costly than hydroxyethyl starch solution (saline: 0.6 USD; hydroxyethyl starch solution: 2.5 USD). Buffered salt solutions, such as compound sodium acetate solutions (e.g., Plasmalyte®), had the highest average cost of crystalloid fluids, costing between 3 and 4 USD per 100 mL.

CONCLUSION

The cost of fluid varies substantially between fluid types and between countries, although normal (0.9%) saline is consistently less costly than colloid preparations and some buffered salt solutions. These data can be used to inform future economic evaluations of fluid preparations.

The evolution of Australian intensive care and its related costs: A narrative review

OBJECTIVE

To conduct a narrative review on the evolution of intensive care and the cost of intensive care services in Australia.

REVIEW METHOD

A narrative review using a search of online medical databases and grey literature with keyword verification via Delphi-technique.

DATA SOURCES

Using Medical Subject Headings and keywords (intensive care, critical care, mechanical ventilation, renal replacement therapy, extracorporeal membrane oxygenation, monitoring, staffing, cost, cost analysis) we searched MEDLINE, PubMed, CINAHL, Embase, Google and Google Scholar.

RESULTS

The search yielded 30 articles from which we provide a narrative synthesis on the evolving intensive care practice in relation to key service elements and therapies. For the review of costs, we found five relevant publications and noted significant variation in methods used to cost ICU. Notwithstanding the limitations of the methods used to cost all publications reported staffing as the primary cost driver, representing up to 71% of costs.

CONCLUSION

Intensive care is a highly specialised medical field, which has developed rapidly and plays an increasingly important role in the provision of hospital care. Despite the increasing importance of the specialty and the known resource intensity there is a paucity of data on the cost of providing this service. In Australia, staffing costs consistently represent the majority of costs associated with operating an ICU. This finding should be interpreted cautiously given the variation of methods used to cost ICU services and the limited number of available studies. Developing standardised methods to consistently estimate ICU costs which can be incorporated in research into the cost-effectiveness of alternate practice is an important step to ensuring cost-effective care.

Charlson comorbidity index derived from chart review or administrative data: agreement and prediction of mortality in intensive care patients

PURPOSE

This study compared the Charlson comorbidity index (CCI) information derived from chart review and administrative systems to assess the completeness and agreement between scores, evaluate the capacity to predict 30-day and 1-year mortality in intensive care unit (ICU) patients, and compare the predictive capacity with that of the Simplified Acute Physiology Score (SAPS) II model.

PATIENTS AND METHODS

Using data from 959 patients admitted to a general ICU in a Norwegian university hospital from 2007 to 2009, we compared the CCI score derived from chart review and administrative systems. Agreement was assessed using % agreement, kappa, and weighted kappa. The capacity to predict 30-day and 1-year mortality was assessed using logistic regression, model discrimination with the c-statistic, and calibration with a goodness-of-fit statistic.

RESULTS

The CCI was complete (n=959) when calculated from chart review, but less complete from administrative data (n=839). Agreement was good, with a weighted kappa of 0.667 (95% confidence interval: 0.596-0.714). The c-statistics for categorized CCI scores from charts and administrative data were similar in the model that included age, sex, and type of admission: 0.755 and 0.743 for 30-day mortality, respectively, and 0.783 and 0.775, respectively, for 1-year mortality. Goodness-of-fit statistics supported the model fit.

CONCLUSION

The CCI scores from chart review and administrative data showed good agreement and predicted 30-day and 1-year mortality in ICU patients. CCI combined with age, sex, and type of admission predicted mortality almost as well as the physiology-based SAPS II.

Predictive Performance of the Simplified Acute Physiology Score (SAPS) II and the Initial Sequential Organ Failure Assessment (SOFA) Score in Acutely Ill Intensive Care Patients: Post-Hoc Analyses of the SUP-ICU Inception Cohort Study

Purpose

Severity scores including the Simplified Acute Physiology Score (SAPS) II and the Sequential Organ Failure Assessment (SOFA) score are used in intensive care units (ICUs) to assess disease severity, predict mortality and in research. We aimed to assess the predictive performance of SAPS II and the initial SOFA score for in-hospital and 90-day mortality in a contemporary international cohort.

Methods

This was a post-hoc study of the Stress Ulcer Prophylaxis in the Intensive Care Unit (SUP-ICU) inception cohort study, which included acutely ill adults from ICUs across 11 countries (n = 1034). We compared the discrimination of SAPS II and initial SOFA scores, compared the discrimination of SAPS II in our cohort with the original cohort, assessed the calibration of SAPS II customised to our cohort, and compared the discrimination for 90-day mortality vs. in-hospital mortality for both scores. Discrimination was evaluated using areas under the receiver operating characteristics curves (AUROC). Calibration was evaluated using Hosmer-Lemeshow’s goodness-of-fit Ĉ-statistic.

Results

AUROC for in-hospital mortality was 0.80 (95% confidence interval (CI) 0.77–0.83) for SAPS II and 0.73 (95% CI 0.69–0.76) for initial SOFA score (P<0.001 for the comparison). Calibration of the customised SAPS II for predicting in-hospital mortality was adequate (P = 0.60). Discrimination of SAPS II was reduced compared with the original SAPS II validation sample (AUROC 0.80 vs. 0.86; P = 0.001). AUROC for 90-day mortality was 0.79 (95% CI 0.76–0.82; P = 0.74 for comparison with in-hospital mortality) for SAPS II and 0.71 (95% CI 0.68–0.75; P = 0.66 for comparison with in-hospital mortality) for the initial SOFA score.

Conclusions

The predictive performance of SAPS II was similar for in-hospital and 90-day mortality and superior to that of the initial SOFA score, but SAPS II’s performance has decreased over time. Use of a contemporary severity score with improved predictive performance may be of value.

Characteristics and outcomes of patients admitted to Spanish ICU: A prospective observational study from the ENVIN-HELICS registry (2006-2011)

OBJECTIVE

To describe the case-mix of patients admitted to intensive care units (ICUs) in Spain during the period 2006-2011 and to assess changes in ICU mortality according to severity level.

DESIGN

Secondary analysis of data obtained from the ENVN-HELICS registry. Observational prospective study.

SETTING

Spanish ICU.

PATIENTS

Patients admitted for over 24h.

INTERVENTIONS

None.

VARIABLES

Data for each of the participating hospitals and ICUs were recorded, as well as data that allowed to knowing the case-mix and the individual outcome of each patient. The study period was divided into two intervals, from 2006 to 2008 (period 1) and from 2009 to 2011 (period 2). Multilevel and multivariate models were used for the analysis of mortality and were performed in each stratum of severity level.

RESULTS

The study population included 142,859 patients admitted to 188 adult ICUs. There was an increase in the mean age of the patients and in the percentage of patients >79 years (11.2% vs. 12.7%, P<0.001). Also, the mean APACHE II score increased from 14.35±8.29 to 14.72±8.43 (P<0.001). The crude overall intra-UCI mortality remained unchanged (11.4%) but adjusted mortality rate in patients with APACHE II score between 11 and 25 decreased modestly in recent years (12.3% vs. 11.6%, odds ratio=0.931, 95% CI 0.883-0.982; P=0.008).

CONCLUSION

This study provides observational longitudinal data on case-mix of patients admitted to Spanish ICUs. A slight reduction in ICU mortality rate was observed among patients with intermediate severity level.

Worrisome trends in incidence and mortality of candidemia in intensive care units (Paris area, 2002-2010)

Purpose

To analyze trends in incidence and mortality of candidemia in intensive care units (ICUs) vs. non-ICU hospitalized patients and to determine risk factors for infection by specific species and for death.

Methods

Active hospital-based surveillance program of incident episodes of candidemia due to common species in 24 tertiary care hospitals in the Paris area, France between October 2002 and September 2010.

Results

Among 2,507 adult cases included, 2,571 Candida isolates were collected and species were C. albicans (56 %), C. glabrata (18.6 %), C. parapsilosis (11.5 %), C. tropicalis (9.3 %), C. krusei (2.9 %), and C. kefyr (1.8 %). Candidemia occurred in ICU in 1,206 patients (48.1 %). When comparing ICU vs. non-ICU patients, the former had significantly more frequent surgery during the past 30 days, were more often preexposed to fluconazole and treated with echinocandin, and were less frequently infected with C. parapsilosis. Risk factors and age remained unchanged during the study period. A significant increased incidence in the overall population and ICU was found. The odds of being infected with a given species in ICU was influenced by risk factors and preexposure to fluconazole and caspofungin. Echinocandins initial therapy increased over time in ICU (4.6 % first year of study, to 48.5 % last year of study, p < 0.0001). ICU patients had a higher day-30 death rate than non-ICU patients (odds ratio [OR] 2.12; 95 % confidence interval [CI] 1.66–2.72; p < 0.0001). The day-30 and early (<day 8) death rates increased over time in ICU (from 41.5 % the first to 56.9 % the last year of study (p = 0.001) and 28.7–38.8 % (p = 0.0292), respectively). Independent risk factors for day-30 death in ICU were age, arterial catheter, Candida species, preexposure to caspofungin, and lack of antifungal therapy at the time of blood cultures results (p < 0.05).

Conclusions

The availability of new antifungals and the publication of numerous guidelines did not prevent an increase of candidemia and death in ICU patients in the Paris area.

Mortality in elderly ICU patients: a cohort study

BACKGROUND

The population is aging. We examined changes in the proportion of elderly (≥ 80 years) intensive care unit (ICU) patients during 2005-2011 and the association between age and mortality controlling for preexisting morbidity.

METHODS

Through the Danish National Patient Registry, we identified a cohort of 49,938 ICU admissions (47,596 patients) in Northern Denmark from 2005 to 2011. Patients were subdivided in age groups (15-49, 50-64, 65-79 and ≥ 80 years) and calendar year. We estimated 30-day and 31-365-day mortality and mortality rate ratios (MRRs), stratified by admission type (medical and elective/acute surgical patients). Mortality was compared between age groups adjusting for sex and preexisting morbidity using 50-64-year-olds as reference.

RESULTS

The proportion of elderly patients increased from 11.7% of all ICU patients in 2005 to 13.8% in 2011. Among the elderly, the 30-day mortality was 43.7% in medical, 39.6% in acute surgical, and 11.6% in elective surgical ICU patients. The corresponding adjusted 30-day MRRs compared with the 50-64-year-olds were 2.7 [95% confidence interval (CI) 2.5-3.0] in medical, 2.7 (95% CI 2.4-3.0) in acute surgical, and 5.2 (95% CI 4.1-6.6) in elective surgical ICU patients. The 31-365-day mortality among elderly patients was 25.4% in medical, 26.9% in acute, and 11.9% in elective surgical ICU patients, corresponding to adjusted MRRs of 2.5 (95% CI 2.1-2.9), 2.2 (95% CI 1.9-2.5), and 1.9 (95% CI 1.6-2.3), respectively.

CONCLUSIONS

During 2005-2011, there was an 18% increase in the proportion of elderly ICU patients. Advancing age is associated with increased mortality even after controlling for preexisting morbidity.

Patient comorbidities and complications after spinal surgery: a societal-based cost analysis

STUDY DESIGN

Prospective observational study.

OBJECTIVE

To determine how patient comorbidities and perioperative complications after spinal surgery affect the health care costs to society.

SUMMARY OF BACKGROUND DATA

Despite efforts to reduce adverse events related to spinal surgery, complications are common and significantly increased by patient comorbidities.

METHODS

Patients who underwent spinal surgery at a tertiary academic center during a 6-month period (May 2008 to December 2008) were prospectively followed. All demographic data, comorbidities, procedural information, and complications to 30-day follow-up were recorded. Diagnosis-Related Group codes and Current Procedural Terminology codes were captured for each patient. Direct costs were estimated from a societal perspective, using 2008 Medicare rates of reimbursement. A multivariable analysis was performed to assess the impact of specific patient comorbidities and complications on total health care costs.

RESULTS

A total of 226 cases were analyzed. The mean cost of care for cases with complications was greater than that for cases without complications ($13,518.35 [95% confidence interval (CI), $9378.80-$17,657.90]; P < 0.0001). These results were consistent across degenerative, traumatic, and tumor/infection preoperative diagnoses. Cases with major complications were more costly than those with minor complications ($13,714.88 [CI, $6353.02-$21,076.74]; P = 0.0001). Systemic malignancy and preoperative neurological comorbidity were each associated with an increase in the cost of care ($7919 [CI, $2073-$15,225]; P = 0.006] and $5508 [CI, $814-$11,198; P = 0.02]), respectively, when compared with a baseline cost of care derived from all cases in the database. The cost of care was increased by pulmonary complications ($7233 [CI, $3982.53-$11,152.88]; P < 0.0001), instrumentation malposition ($6968 [CI, $1705.90-$14,277.16]; P = 0.0062), new neurological deficit ($4537 [CI, $863.95-$9274.30]; P = 0.013), and by wound infection ($4067 [CI, $1682.79-$6872.39]; P = 0.0004), after adjustment for covariates.

CONCLUSION

Both minor and major complications were found to increase the cost of care in a prospective assessment of spine surgery complications. Specific patient comorbidities and perioperative complications are associated with significant increases in the total cost of care to society.

The impact of pre-admission morbidity level on 3-year mortality after intensive care: a Danish cohort study

BACKGROUND

Chronic diseases are common among intensive care unit (ICU) patients and may worsen their prognosis. We examined the prevalence and impact of pre-admission/index morbidity among ICU patients compared with a general population cohort.

METHODS

Our study encompassed all 28,172 adult patients admitted to ICUs in northern Denmark in 2005-2007 and 281,671 age- and sex-matched individuals from the general population. We used a nationwide hospital registry to obtain a 5-year history of 19 chronic diseases and computed Charlson Comorbidity Index (CCI) for each study participant and grouped them into low (CCI=0), moderate (CCI=1-2), and high (CCI=3+) morbidity levels. We computed mortality and mortality rate ratios (MRRs) adjusted for confounders, and compared the mortality between ICU patients and the general population cohort.

RESULTS

Low, moderate, and high pre-admission morbidity levels were present in 51.5%, 34.1%, and 14.4% of ICU patients, respectively. In these groups, 30-day mortality was 10.8%, 18.4%, and 26.7%, respectively. Three-year mortality was 21.3%, 43.1%, and 63.2%, respectively. The adjusted 30-day MRR was 1.30 [95% confidence intervals (CI): 1.21-1.39] and 1.86 (95% CI: 1.71-2.01) for ICU patients with moderate and high morbidity levels, both compared with a low morbidity level. The general population had a lower morbidity level and mortality at all morbidity levels throughout the study period. Interaction between ICU admission and high morbidity level added 5.1% to the mortality during the second and third year of follow-up.

CONCLUSION

A high pre-admission morbidity level was frequent among ICU patients and associated with a worsened prognosis. Morbidity had more impact on mortality among ICU patients compared with a general population cohort.

Charlson score is a robust predictor of 30-day complications following spinal metastasis surgery

STUDY DESIGN

Retrospective chart review.

OBJECTIVE

To identify predictors of 30-day complications after the surgical treatment of spinal metastasis.

SUMMARY OF BACKGROUND DATA

Surgical treatment of spinal metastasis is considered palliative with the aim of reducing or delaying neurologic deficit. Postoperative complication rates as high as 39% have been reported in the literature. Complications may impact patient quality of life and increase costs; therefore, an understanding of which preoperative variables best predict 30-day complications will help risk-stratify patients and guide therapeutic decision making and informed consent.

METHODS

We retrospectively reviewed 200 cases of spinal metastasis surgically treated at Stanford Hospital between 1999 and 2009. Multiple logistic regression was performed to determine which preoperative variables were independent predictors of 30-day complications.

RESULTS

Sixty-eight patients (34%) experienced one or more complications within 30 days of surgery. The most common complications were respiratory failure, venous thromboembolism, and pneumonia. On multivariate analysis, Charlson Comorbidity Index score was the most significant predictor of 30-day complications. Patients with a Charlson score of two or greater had over five times the odds of a 30-day complication as patients with a score of zero or one.

CONCLUSION

After adjusting for demographic, oncologic, neurologic, operative, and health factors, Charlson score was the most robust predictor of 30-day complications. A Charlson score of two or greater should be considered a surgical risk factor for 30-day complications, and should be used to risk-stratify surgical candidates. If complications are anticipated, medical staff can prepare in advance, for instance, scheduling aggressive ICU care to monitor for and treat complications. Finally, Charlson score should be controlled for in future spinal metastasis outcomes studies and compared to other comorbidity assessment tools.