High-quality Clinical Database Research Articles

A new measure of acute physiological derangement for patients with exacerbations of obstructive airways disease: The COPD and Asthma Physiology Score

Decisions about how to treat patients with acute exacerbations of obstructive airways disease-chronic obstructive pulmonary disease (COPD), asthma or mixed diagnoses-often require an understanding of prognosis. This depends on the severity of the acute deterioration and the patient's functional reserve. There are currently no validated disease-specific scores that measure the severity of the acute exacerbation. To develop an acute physiology score for exacerbations of obstructive airways disease. Secondary analysis of a high-quality clinical database, the Case Mix Programme Database. One hundred and sixty-eight adult, general critical care units in England, Wales and Northern Ireland. A total of 8527 patients with obstructive airways disease were identified with a mean (SD) age of 65.9 (9.7) years and hospital mortality of 35.5%. The COPD and Asthma Physiology Score (CAPS) was developed using logistic regression. The CAPS included eight variables: heart rate, mean arterial blood pressure, pH, sodium, urea, creatinine, albumin and white blood cell count. The score had fair discrimination with an area under the receiver operating characteristic curve of 0.718. This performance was reproduced in a further validation dataset of 7957 patients. The discrimination of the CAPS in these validation data exceeded that of the acute physiology scores from APACHE II and III and the physiological components of SAPS II. The CAPS can be used to estimate the prognostic impact of physiological derangements accompanying an acute exacerbation of obstructive airways disease and has the potential for even greater predictive performance when combined with measures of a patient's functional reserve.

Case mix, outcome and activity for patients admitted to intensive care units requiring chronic renal dialysis: a secondary analysis of the ICNARC Case Mix Programme Database

IntroductionThis report describes the case mix, outcome and activity for admissions to intensive care units (ICUs) of patients who require prior chronic renal dialysis for end-stage renal failure (ESRF), and investigates the effect of case mix factors on outcome.MethodsThis was a secondary analysis of a high-quality clinical database, namely the Intensive Care National Audit & Research Centre (ICNARC) Case Mix Programme Database, which includes 276,731 admissions to 170 adult ICUs across England, Wales and Northern Ireland from 1995 to 2004.ResultsDuring the eight year study period, 1.3% (n = 3,420) of all patients admitted to ICU were receiving chronic renal dialysis before ICU admission. This represents an estimated ICU utilization of six admissions (32 bed-days) per 100 dialysis patient-years. The ESRF group was younger (mean age 57.3 years versus 59.5 years) and more likely to be male (60.2% versus 57.9%) than those without ESRF. Acute Physiology and Chronic Health Evaluation II score and Acute Physiology Score revealed greater severity of illness on admission in patients with ESRF (mean 24.7 versus 16.6 and 17.2 versus 12.6, respectively). Length of stay in ICU was comparable between groups (median 1.9 days versus 1.8 days) and ICU mortality was only slightly elevated in the ESRF group (26.3% versus 20.8%). However, the ESRF group had protracted overall hospital stay (median 25 days versus 17 days), and increased hospital mortality (45.3% versus 31.2%) and ICU readmission (9.0% vs. 4.7%). Multiple logistic regression analysis adjusted for case mix identified the increased hospital mortality to be associated with increasing age, emergency surgery and nonsurgical cases, cardiopulmonary resuscitation before ICU admission and extremes of physiological norms. The adjusted odds ratio for ultimate hospital mortality associated with chronic renal dialysis was 1.24 (95% confidence interval 1.13 to 1.37).ConclusionPatients with ESRF admitted to UK ICUs are more likely to be male and younger, with a medical cause of admission, and to have greater severity of illness than the non-ESRF population. Outcomes on the ICU were comparable between the two groups, but those patients with ESRF had greater readmission rates, prolonged post-ICU hospital stay and increased post-ICU hospital mortality. This study is by far the largest comparative outcome analysis to date in patients with ESRF admitted to the ICU. It may help to inform clinical decision-making and resource requirements for this patient population.

La recherche sur les bases de données en réanimation

A huge amount of medical data is now available for clinical research because of the computerization of the healthcare system. If data records are complete and accurate and use standard definitions it becomes possible to develop high quality medical databases and subsequent high quality clinical research. Research on high quality clinical databases should become a useful complement to the randomised controlled trials. However, an important implication of a multidisciplinary (Intensive Care Unit physicians and nurses, biostatisticians) steering committee is needed to maintain the exactness and the completeness of recorded data, to reinforce the motivation of the investigators and to define orientation of the database and future researches.

Development and implementation of a high-quality clinical database: the Australian and New Zealand Intensive Care Society Adult Patient Database

Objective To describe the development of a binational intensive care database. Setting One hundred thirty-eight intensive care units (ICUs) in Australia and New Zealand. Methods A structure was developed to enable ICUs to submit data for central and local analysis. Reports were developed to allow comparison with similar ICU types and against published mortality prediction models. The database was evaluated according to ( a) the criteria of the Directory of Clinical Databases (DoCDat) and ( b) a proposed framework for data quality assurance in medical registries. Results Between January 1987 and December 2003, 444 147 data sets were collected from 121 (72.5%) of 167 Australian and 10 (37.0%) of 27 New Zealand ICUs. Data sets from more than 60 000 ICU admissions were submitted in 2003. Overall hospital mortality was 14.5%. The mean quality level achieved according to DoCDat criteria was high as was performance against a proposed framework for data quality. The provision of no-cost software has been vitally important to the success of the database. Conclusion A high-quality ICU database has successfully been implemented in Australia and New Zealand and is now used as a routine quality assurance and peer review tool. Similar developments may be both possible and desirable in other countries.

The epidemiology of severe sepsis in England, Wales and Northern Ireland, 1996 to 2004: secondary analysis of a high quality clinical database, the ICNARC Case Mix Programme Database

IntroductionTo evaluate the impact of recent evidence-based treatments for severe sepsis in routine clinical care requires an understanding of the underlying epidemiology, particularly with regard to trends over time. We interrogated a high quality clinical database to examine trends in the incidence and mortality of severe sepsis over a nine-year period.MethodsAdmissions with severe sepsis occurring at any time within 24 hours of admission to critical care were identified to an established methodology using raw physiological data from the Intensive Care National Audit & Research Centre (ICNARC) Case Mix Programme Database, containing data from 343,860 admissions to 172 adult, general critical care units in England, Wales and Northern Ireland between December 1995 and January 2005. Generalised linear models were used to assess changes in the incidence, case mix, outcomes and activity of these admissions.ResultsIn total, 92,672 admissions (27.0%) were identified as having severe sepsis in the first 24 hours following admission. The percentage of admissions with severe sepsis during the first 24 hours rose from 23.5% in 1996 to 28.7% in 2004. This represents an increase from an estimated 18,500 to 31,000 admissions to all 240 adult, general critical care units in England, Wales and Northern Ireland. Hospital mortality for admissions with severe sepsis decreased from 48.3% in 1996 to 44.7% in 2004, but the total number of deaths increased from an estimated 9,000 to 14,000. The treated incidence of severe sepsis per 100,000 population rose from 46 in 1996 to 66 in 2003, with the associated number of hospital deaths per 100,000 population rising from 23 to 30.ConclusionThe population incidence of critical care admission with severe sepsis during the first 24 hours and associated hospital deaths are increasing. These baseline data provide essential information to those wishing to evaluate the introduction of the Surviving Sepsis Campaign care bundles in UK hospitals.

Community-acquired pneumonia on the intensive care unit: secondary analysis of 17,869 cases in the ICNARC Case Mix Programme Database

IntroductionThis paper describes the case mix, outcome and activity for admissions to intensive care units (ICUs) with community-acquired pneumonia (CAP).MethodsWe conducted a secondary analysis of a high quality clinical database, the Intensive Care National Audit & Research Centre (ICNARC) Case Mix Programme Database, of 301,871 admissions to 172 adult ICUs across England, Wales and Northern Ireland, 1995 to 2004. Cases of CAP were identified from pneumonia admissions excluding nosocomial pneumonias and the immuno-compromised. It was not possible to review data from the time of hospital admission; therefore, some patients who developed hospital-acquired/nosocomial pneumonia may have been included.ResultsWe identified 17,869 cases of CAP (5.9% of all ICU admissions). There was a 128% increase in admissions for CAP from 12.8 per unit to 29.2 per unit during the study period compared to only a 24% rise in total ICU admissions (p < 0.001). Eighty-five percent of admissions were from within the same hospital. Fifty-nine percent of cases were admitted to the ICU <2 days, 21.5% between 2 and 7 days, and 19.5% >7 days after hospital admission. Between 1995 and 1999 and 2000 and 2004 there was a rise in admissions from accident and emergency (14.8% to 16.8%; p < 0.001) and high dependency units (6.9% to 11.9%; p < 0.001) within the same hospital, those aged >74 (18.5 to 26.1%; p < 0.001), and mean APACHE II score (6.83 to 6.91; p < 0.001). There was a fall in past history of severe respiratory problems (8.7% to 6.4%; p < 0.001), renal replacement therapy (1.6% to 1.2%; p < 0.01), steroid treatment (3.4% to 2.8%; p < 0.05), sedation/paralysis (50.2% to 40.4%; p < 0.001), cardiopulmonary resuscitation prior to admission (7.5% to 5.5%; p < 0.001), and septic shock (7.3% to 6.6%; p < 0.001). ICU mortality was 34.9% and ultimate hospital mortality 49.4%. Mortality was 46.3% in those admitted to the ICU within 2 days of hospital admission rising to 50.4% in those admitted at 2 to 7 days and 57.6% in those admitted after 7 days following hospital admission.ConclusionCAP makes up a small, but important and rising, proportion of adult ICU admissions. Survival of over half of all cases vindicates the use of ICU facilities in CAP management. Nevertheless, overall mortality remains high, especially in those admitted later in their hospital stay.

Register now: validity later

Register now: validity later

Admissions to intensive care units from emergency departments: a descriptive study

Objectives: To describe the case mix, activity, and outcome for admissions to intensive care units (ICUs) from emergency departments (EDs). Design: An observational study using data from a high quality...

Case mix and outcomes for admissions to UK adult, general critical care units with chronic obstructive pulmonary disease: a secondary analysis of the ICNARC Case Mix Programme Database

IntroductionChronic obstructive pulmonary disease (COPD) is a common cause of admission to intensive care units (ICUs) in the UK. This report describes the case mix and outcomes of these patients and explores associations of measures of case mix available in the first 24 hours with outcome.MethodWe conducted a secondary analysis of a high quality clinical database, the ICNARC Case Mix Programme Database, of 129,647 admissions to 128 adult, general critical care units across England, Wales and Northern Ireland for the period from 1995 to 2001.ResultsNonsurgical admissions with COPD accounted for 3752 admissions (2.9% of all admissions). Patients were acidotic (median pH 7.26, interquartile range [IQR] 7.18–7.33), hypercapnic (median arterial CO2 tension 8.7, IQR 6.9–10.7) and hypoxic (median arterial O2 tension/fractional inspired oxygen gradient 22.9, IQR 17.2–29.6). Overall, 2775 (73.9%) were definitely intubated and 278 (7.4%) were probably intubated in the first 24 hours in the ICU. The median (IQR) ICU length of stay was 4.0 (1.6–9.4) days and the hospital length of stay was 16 (9–29) days. a total of 827 patients (23.1%) died in the admitting ICU and 1322 (38.3%) died during hospital admission. Age, presence of severe respiratory disease, length of stay in hospital before critical care admission, cardiopulmonary resuscitation within 24 hours before admission, intubation status in first 24 hours in critical care, pH, arterial oxygen tension/fractional inspired oxygen gradient, albumin, cardiovascular organ failure, neurological organ failure and renal organ failure all had independent associations with hospital mortality. Respiratory organ failure had a significant independent association with decreased hospital mortality.ConclusionNonsurgical patients with COPD represent an important group of patients admitted to UK ICUs. The presence of single organ respiratory failure in the first 24 hours in critical care identifies patients with a 70% chance of surviving to leave hospital.

Characteristics and outcome for admissions to adult, general critical care units with acute severe asthma: a secondary analysis of the ICNARC Case Mix Programme Database

IntroductionThis report describes the case mix, outcome and activity (duration of intensive care unit [ICU] and hospital stay, inter-hospital transfer, and readmissions to the ICU) for admissions to ICUs for acute severe asthma, and investigates the effect of case mix factors on outcome.MethodsWe conducted a secondary analysis of data from a high-quality clinical database (the Intensive Care National Audit and Research Centre [ICNARC] Case Mix Programme Database) of 129,647 admissions to 128 adult, general critical care units across England, Wales and Northern Ireland over the period 1995–2001.ResultsAsthma accounted for 2152 (1.7%) admissions, and in 57% mechanical ventilation was employed during the first 24 hours in the ICU. A total of 147 (7.1%) patients died in intensive care and 199 (9.8%) died before discharge from hospital. The mean age was 43.6 years, and the ratio of women to men was 2:1. Median length of stay was 1.5 days in the ICU and 8 days in hospital. Older age, female sex, having received cardiopulmonary resuscitation (CPR) within 24 hours before admission, having suffered a neurological insult during the first 24 hours in the ICU, higher heart rate, and hypercapnia were associated with greater risk for in-hospital death after adjusting for Acute Physiology and Chronic Health Evaluation II score. CPR before admission, neurological insult, hypoxaemia and hypercapnia were associated with receipt of mechanical ventilation after adjusting for Acute Physiology and Chronic Health Evaluation II score.ConclusionICU admission for asthma is relatively uncommon but remains associated with appreciable in-hospital mortality. The greatest determinant of poor hospital survival in asthma patients was receipt of CPR within 24 hours before admission to ICU. Clinical management of these patients should be directed at preventing cardiac arrest before admission.

Characteristics and outcome for admissions to adult, general critical care units with acute severe asthma: a secondary analysis of the ICNARC Case Mix Programme Database.

This report describes the case mix, outcome and activity (duration of intensive care unit [ICU] and hospital stay, inter-hospital transfer, and readmissions to the ICU) for admissions to ICUs for acute severe asthma, and investigates the effect of case mix factors on outcome. We conducted a secondary analysis of data from a high-quality clinical database (the Intensive Care National Audit and Research Centre [ICNARC] Case Mix Programme Database) of 129,647 admissions to 128 adult, general critical care units across England, Wales and Northern Ireland over the period 1995-2001. Asthma accounted for 2152 (1.7%) admissions, and in 57% mechanical ventilation was employed during the first 24 hours in the ICU. A total of 147 (7.1%) patients died in intensive care and 199 (9.8%) died before discharge from hospital. The mean age was 43.6 years, and the ratio of women to men was 2:1. Median length of stay was 1.5 days in the ICU and 8 days in hospital. Older age, female sex, having received cardiopulmonary resuscitation (CPR) within 24 hours before admission, having suffered a neurological insult during the first 24 hours in the ICU, higher heart rate, and hypercapnia were associated with greater risk for in-hospital death after adjusting for Acute Physiology and Chronic Health Evaluation II score. CPR before admission, neurological insult, hypoxaemia and hypercapnia were associated with receipt of mechanical ventilation after adjusting for Acute Physiology and Chronic Health Evaluation II score. ICU admission for asthma is relatively uncommon but remains associated with appreciable in-hospital mortality. The greatest determinant of poor hospital survival in asthma patients was receipt of CPR within 24 hours before admission to ICU. Clinical management of these patients should be directed at preventing cardiac arrest before admission.

Case mix, outcome and length of stay for admissions to adult, general critical care units in England, Wales and Northern Ireland: the Intensive Care National Audit & Research Centre Case Mix Programme Database.

The present paper describes the methods of data collection and validation employed in the Intensive Care National Audit & Research Centre Case Mix Programme (CMP), a national comparative audit of outcome for adult, critical care admissions. The paper also describes the case mix, outcome and activity of the admissions in the Case Mix Programme Database (CMPD). The CMP collects data on consecutive admissions to adult, general critical care units in England, Wales and Northern Ireland. Explicit steps are taken to ensure the accuracy of the data, including use of a dataset specification, of initial and refresher training courses, and of local and central validation of submitted data for incomplete, illogical and inconsistent values. Criteria for evaluating clinical databases developed by the Directory of Clinical Databases were applied to the CMPD. The case mix, outcome and activity for all admissions were briefly summarised. The mean quality level achieved by the CMPD for the 10 Directory of Clinical Databases criteria was 3.4 (on a scale of 1 = worst to 4 = best). The CMPD contained validated data on 129,647 admissions to 128 units. The median age was 63 years, and 59% were male. The mean Acute Physiology and Chronic Health Evaluation II score was 16.5. Mortality was 20.3% in the CMP unit and was 30.8% at ultimate discharge from hospital. Nonsurvivors stayed longer in intensive care than did survivors (median 2.0 days versus 1.7 days in the CMP unit) but had a shorter total hospital length of stay (9 days versus 16 days). Results for the CMPD were comparable with results from other published reports of UK critical care admissions. The CMP uses rigorous methods to ensure data are complete, valid and reliable. The CMP scores well against published criteria for high-quality clinical databases.

Case mix, outcome and length of stay for admissions to adult, general critical care units in England, Wales and Northern Ireland: the Intensive Care National Audit & Research Centre Case Mix Programme Database

IntroductionThe present paper describes the methods of data collection and validation employed in the Intensive Care National Audit & Research Centre Case Mix Programme (CMP), a national comparative audit of outcome for adult, critical care admissions. The paper also describes the case mix, outcome and activity of the admissions in the Case Mix Programme Database (CMPD).MethodsThe CMP collects data on consecutive admissions to adult, general critical care units in England, Wales and Northern Ireland. Explicit steps are taken to ensure the accuracy of the data, including use of a dataset specification, of initial and refresher training courses, and of local and central validation of submitted data for incomplete, illogical and inconsistent values. Criteria for evaluating clinical databases developed by the Directory of Clinical Databases were applied to the CMPD. The case mix, outcome and activity for all admissions were briefly summarised.ResultsThe mean quality level achieved by the CMPD for the 10 Directory of Clinical Databases criteria was 3.4 (on a scale of 1 = worst to 4 = best). The CMPD contained validated data on 129,647 admissions to 128 units. The median age was 63 years, and 59% were male. The mean Acute Physiology and Chronic Health Evaluation II score was 16.5. Mortality was 20.3% in the CMP unit and was 30.8% at ultimate discharge from hospital. Nonsurvivors stayed longer in intensive care than did survivors (median 2.0 days versus 1.7 days in the CMP unit) but had a shorter total hospital length of stay (9 days versus 16 days). Results for the CMPD were comparable with results from other published reports of UK critical care admissions.ConclusionsThe CMP uses rigorous methods to ensure data are complete, valid and reliable. The CMP scores well against published criteria for high-quality clinical databases.

Improving the use of clinical databases

The need for high quality clinical databases has been thoroughly documented1 2 3 They offer the opportunity to carry out evaluative research and clinical audit, inform the planning and management...

High-quality clinical databases: breaking down barriers

The need for accurate systematic information to inform not only clinical practice and health-services management but also evaluation research and clinical audit is now well recognised. Less well recognised are the benefits that could result if the proponents of each of these activities combined their resources to obtain the data they need. Irrespective of the uses to which they wish to put the data, clinicians, managers, consumers, and researchers all need data, from consecutive cases, that are complete and accurate, that are based on standard definitions of clinical disorders, interventions, and outcomes, and that include information on those characteristics of patients that affect outcome. Anyone familiar with administrative data collected routinely in most health systems will recognise the inadequacy of information from such sources. In response to such failings, groups of clinicians in many countries have established their own high-quality clinical databases (HQCDs). 1 Pryor DB Califf RM Harrell FE et al. Clinical data bases: accomplishments and unrealized potential. Med Care. 1985; 23: 623-647 Crossref PubMed Scopus (73) Google Scholar Until recently, most schemes have been regional rather than national—in the USA, cardiac surgery in New York State; 2 Hannan EL Kilburn HJr O'Donnell JF Lukacik G Shields EP Adult open heart surgery in New York State: an analysis of risk factors and hospital mortality rates. JAMA. 1990; 264: 2768-2774 Crossref PubMed Scopus (481) Google Scholar in the UK, surgery in Lothian in the 1970s, 3 Gruer R Gordon DS Gunn AA Ruckley CV Audit of surgical audit. Lancet. 1986; i: 23-26 Summary Scopus (67) Google Scholar followed by obstetrics in the North West Thames region, orthopaedics in the Trent and North West region, and haematology in the Northern region in the 1980s. 4 Charlton BG Taylor PRA Proctor SJ The PACE (population-adjusted clinical epidemiology) strategy: a new approach to multi-centred clinical research. Q J Med. 1997; 90: 147-150 Crossref Scopus (42) Google Scholar The most advanced and ambitious work in this area in the UK has been in intensive care. 5 Rowan KM Intensive Care National Audit and Research Centre— past, present and future. Care Critically III. 1994; 10: 148-149 Google Scholar Despite recognition of the potential value of such databases for audit, there is less awareness of how they can be used to aid clinical practice, manage services, and evaluate health technologies.

Discussion

The need to evaluate drugs' effects in real clinical practice is increasingly important. Randomized clinical trials (RCTs) and database analyses (DBA) are the two main methods to assess treatments effectiveness. RCTs remain the "gold standard" for comparing alternative treatments. However, they are conducted under strict, protocol-driven conditions that may limit their generalizability. Advantages of new high quality clinical databases, on the other hand, include the simple and economic access to large number and range of cases, and the ability to capture all aspects of actual medical practice. The main potential limitation of DBA is the potential for comparison bias due to the lack of randomization. Despite the efforts to design naturalistic trials and to use sophisticated statistical techniques to minimize selection bias, the inherent limitations of both methods (problems of external and internal validity, respectively) have not been completely solved. Thus, the actual challenge is the development of some new strategy capable of generating results with an acceptable balance between internal and external validity. As randomization is essential to minimize comparison bias, we point out the possibility to include randomization modules in computer-based patient records. The theoretical foundation of these "randomized database studies" is the simultaneous use of both experimental and observational methods in the assessment of drugs' effectiveness. The progressive standardization of clinical practice and the development and adoption of improved computer-based patient records could facilitate the use of this new research strategy.