Diagnosis of Inflammatory Bowel Disease-Associated Peripheral Arthritis: A Systematic Review.

BACKGROUND: Inflammatory bowel disease (IBD)-associated peripheral spondyloarthritis (pSpA) decreases quality of life and remains poorly understood. Given the prevalence of this condition and its negative impact, it is surprising that evidence-based disease definitions and diagnostic strategies are lacking. This systematic review summarizes available data to facilitate development and validation of diagnostics, patient-reported outcomes, and imaging indices specific to this condition. METHODS: A literature search was conducted. Consensus or classification criteria, case series, cross-sectional studies, cohort studies, and randomized controlled trials related to diagnosis were included. RESULTS: A total of 44 studies reporting data on approximately 1500 patients with pSpA were eligible for analysis. Data quality across studies was only graded as fair to good. Due to large heterogeneity, meta-analysis was not possible. The majority of studies incorporated patient-reported outcomes and a physical examination. A total of 13 studies proposed or validated screening tools, consensus, classification, or consensus criteria. A total of 28 studies assessed the role of laboratory tests, none of which were considered sufficiently accurate for use in diagnosis. A total of 17 studies assessed the role of imaging, with the available literature insufficient to fully endorse any imaging modality as a robust diagnostic tool. CONCLUSIONS: This review highlights existing inconsistency and lack of a clear diagnostic approach for IBD-associated pSpA. Given the absence of an evidence-based approach, a combination of existing criteria and physician assessment should be utilized. To address this issue comprehensively, our future efforts will be directed toward pursuit of a multidisciplinary approach aimed at standardizing evaluation and diagnosis of IBD-associated pSpA.

This systematic review highlights the lack of an evidence-based approach to the diagnosis of inflammatory bowel disease­associated peripheral spondyloarthritis and the need to standardize evaluation and diagnosis via multidisciplinary collaboration with development of patient-reported outcomes and imaging indices.

A Systematic Review of Metrics Utilized in the Selection and Prediction of Future Performance of Residents in the United States.

Background Aligning resident and training program attributes is critical. Many programs screen and select residents using assessment tools not grounded in available evidence. This can introduce bias and inappropriate trainee recruitment. Prior reviews of this literature did not include the important lens of diversity, equity, and inclusion (DEI). Objective This study's objective is to summarize the evidence linking elements in the Electronic Residency Application Service (ERAS) application with selection and training outcomes, including DEI factors. Methods A systematic review was conducted on March 30, 2022, concordant with PRISMA guidelines, to identify the data supporting the use of elements contained in ERAS and interviews for residency training programs in the United States. Studies were coded into the topics of research, awards, United States Medical Licensing Examination (USMLE) scores, personal statement, letters of recommendation, medical school transcripts, work and volunteer experiences, medical school demographics, DEI, and presence of additional degrees, as well as the interview. Results The 2599 identified unique studies were reviewed by 2 authors with conflicts adjudicated by a third. Ultimately, 231 meeting inclusion criteria were included (kappa=0.53). Conclusions Based on the studies reviewed, low-quality research supports use of the interview, Medical Student Performance Evaluation, personal statement, research productivity, prior experience, and letters of recommendation in resident selection, while USMLE scores, grades, national ranking, attainment of additional degrees, and receipt of awards should have a limited role in this process.

Safety and Efficacy of Prophylactic Amiodarone After Left Ventricular Assist Device.

The prophylactic use of amiodarone to reduce the incidence of postoperative arrhythmias is effective for patients undergoing general cardiac surgeries; however, no data exists for the use of prophylactic amiodarone to prevent postoperative arrhythmias after CF-LVAD. This single-center, retrospective analysis compared patients with CF-LVADs placed between April 2014 and June 2020 who received prophylactic postoperative amiodarone to those who did not. Based on institution practice at the respective times, patients with a CF-LVAD placed between April 2014 and June 2018 were included in the group receiving postoperative amiodarone arrhythmia prophylaxis and patients with a CF-LVAD placed July 2018 to June 2020 were included in the group not receiving arrhythmia prophylaxis. The primary outcome was the incidence of first occurring atrial or ventricular arrhythmia from CF-LVAD placement to 21 days or hospital discharge. Sixty patients received amiodarone for arrhythmia prophylaxis and 27 patients did not receive prophylaxis. The primary outcome occurred in 40% of the prophylaxis group and 66.7% in the no prophylaxis group (RR, 0.60; 95% CI, 0.40-0.90; p = 0.038). In patients receiving CF-LVADs, the use of prophylactic amiodarone was associated with a reduction in the incidence of postoperative arrhythmias, which was driven primarily by a reduction in postoperative atrial arrhythmias, without significantly increasing the rate of amiodarone-related adverse events.

Teams of rural physicians matter: Testing a framework of team effectiveness.

OBJECTIVE: To examine how rural physician team effectiveness predicts outcomes of team performance, team commitment, and intentions to stay. DESIGN: Surveys measuring team climate, team efficacy, and team performance were sent to rural physician team members. Surveys measuring team performance were sent to external observers in supervisory positions. SETTING: Northern Ontario communities. PARTICIPANTS: Rural physicians and external observers, the latter including hospital chief executive officers, family health team executive directors, and clinic managers. MAIN OUTCOMES MEASURES: Total scale scores were generated using mean substitution. Cronbach α was used to assess internal consistencies of team member-level measures. Team-level measures were created by averaging the responses across team members, and intraclass correlation coefficients for each scale of each team of 2 or more members were calculated to yield a measure of rating consistency. A t test was used to assess the possible difference between team performance ratings by team members and external observers. Team-level relationships within the team effectiveness model were assessed using mediated regression, and generalized estimating equations were used to assess the relationships in the model between team-level (team efficacy) and individual-level (affective team commitment and intentions to stay) variables to address the nonindependence of these data. RESULTS: Overall, 70 rural physicians from 26 Rural and Northern Physician Group Agreement communities with 2 or more physicians and 25 external observers from 19 of the 26 Rural and Northern Physician Group Agreement communities participated in the study. The findings showed that team climate (composed of decision making, communication, and conflict resolution measures) positively predicted team efficacy, which in turn positively predicted team performance. This fully mediated set of relationships held whether team performance was rated by the physicians themselves or by the external observers. Team efficacy significantly predicted affective team commitment (b value=0.69, standard error=0.08, Wald =13.89, P<.001) in the first analysis and intentions to stay (b value=0.34, standard error=0.15; Wald =5.42, P=.020) in the second analysis. However, when the other variables impacting physician retention were added to the model in predicting intentions to stay, team efficacy did not predict it above and beyond these additional predictors. CONCLUSION: The findings support initiatives that attempt to enhance physician team effectiveness in rural physician teams by influencing team decision making, communication, and conflict resolution to improve team performance, physician attitudes, and commitment.

Item response theory as a feature selection and interpretation tool in the context of machine learning.

Optimizing the number and utility of features to use in a classification analysis has been the subject of many research studies. Most current models use end-classifications as part of the feature reduction process, leading to circularity in the methodology. The approach demonstrated in the present research uses item response theory (IRT) to select features independent of the end-classification results without the biased accuracies that this circularity engenders. Dichotomous and polytomous IRT models were used to analyze 30 histological breast cancer features from 569 patients using the Wisconsin Diagnostic Breast Cancer data set. Based on their characteristics, three features were selected for use in a machine learning classifier. For comparison purposes, two machine learning-based feature selection protocols were run-recursive feature elimination (RFE) and ridge regression-and the three features selected from these analyses were also used in the subsequent learning classifier. Classification results demonstrated that all three selection processes performed comparably. The non-biased nature of the IRT protocol and information provided about the specific characteristics of the features as to why they are of use in classification help to shed light on understanding which attributes of features make them suitable for use in a machine learning context.

Impact of Adherence to Ibrutinib on Clinical Outcomes in Real-World Patients With Chronic Lymphocytic Leukemia.

BACKGROUND: Chronic lymphocytic leukemia (CLL) is a B-cell neoplasm with clonal expansion of small lymphocytes. Ibrutinib, an irreversible inhibitor of Bruton tyrosine kinase (BTK), is a first-line treatment option, and recent data suggest that strict adherence is directly related to clinical outcomes. OBJECTIVES: The primary objective of this study was to quantify ibrutinib adherence rates in real-world patients with CLL on ibrutinib; secondary outcomes included progression-free survival and overall survival. METHODS: This retrospective study included subjects who were treated at a large academic medical center over approximately 5 years. Subjects were at least 18 years, diagnosed with CLL or small lymphocytic lymphoma, and treated with ibrutinib monotherapy for at least 6 months. Adherence was quantified using the medication possession ratio (MPR), which is the ratio of the sum of days' supply of medication in a period over the number of days in that period, and was based on fill history from the medical center's specialty pharmacy. RESULTS: For the 32 subjects in this study, the mean ibrutinib adherence rate was 91.7% (range, 84.4%-100%). Only 3 subjects had disease progression, and 1 death was recorded while on therapy (all with MPR < 95%); therefore, analyses of clinical outcomes were unable to be assessed due to a low number of events. There were no statistically significant differences in rates of adherence based on baseline characteristics and adverse drug events. CONCLUSION: In patients with CLL treated with ibrutinib, mean adherence was 91.7%, which is lower than rates seen in clinical trials.

Ultrasound-assisted catheter-directed thrombolysis versus systemic anticoagulation alone for submassive pulmonary embolism.

Pulmonary embolism (PE) is a significant contributor to morbidity and mortality in the United States. Catheter-directed, ultrasound-assisted thrombolysis (USAT) uses high-frequency, low-energy ultrasound waves to disaggregate uncrosslinked fibrin fibers and increase thrombus penetration of a locally delivered thrombolytic to treat an acute PE. The purpose of this study is to compare the efficacy and safety of catheter-directed USAT versus systemic anticoagulation alone in submassive PE. This was a single-center, retrospective study of patients with a diagnosis of acute submassive PE from April 4, 2014 to May 1, 2019 at a large, academic medical center. Subjects were split into two different groups based on treatment with either USAT with systemic anticoagulation or systemic anticoagulation alone. The primary outcome was the incidence of severe or life-threatening GUSTO bleeding within 72 h or until hospital discharge if sooner. A total of 130 subjects were included (n = 40 in the USAT group and n = 90 in systemic anticoagulation alone group). Significantly fewer subjects in the USAT group had an active diagnosis of cancer at the time of presentation (7.5% vs 28.9%, p = 0.006). There was no difference in severe or life-threatening GUSTO bleeding or any component of the GUSTO bleeding definitions. Administration of USAT with systemic anticoagulation was well-tolerated when compared to systemic anticoagulation alone, but bias may have led to selection of patients for USAT with a lower bleeding risk and higher functional status at baseline.

Novel Feature Selection for Artificial Intelligence Using Item Response Theory for Mortality Prediction.

Feature selection is a critical component in supervised machine learning classification analyses. Extraneous features introduce noise and inefficiencies into the system leading to a need for feature reduction techniques. Many feature reduction models use the end-classification results in the feature reduction process, committing a circular error. Item Response Theory (IRT) examines the characteristics of features independent of the end-classification results, and provides high levels of information regarding feature utility. A two-parameter dichotomous IRT model was used to analyze 18 features from an intensive care unit data set with 2520 cases. The classification results showed that the features selected via IRT were comparable to that using more traditional machine learning approaches. Strengths and limitations of the IRT selection protocol are discussed.

Using Item Response Theory for Explainable Machine Learning in Predicting Mortality in the Intensive Care Unit: Case-Based Approach.

BACKGROUND: Supervised machine learning (ML) is being featured in the health care literature with study results frequently reported using metrics such as accuracy, sensitivity, specificity, recall, or F1 score. Although each metric provides a different perspective on the performance, they remain to be overall measures for the whole sample, discounting the uniqueness of each case or patient. Intuitively, we know that all cases are not equal, but the present evaluative approaches do not take case difficulty into account. OBJECTIVE: A more case-based, comprehensive approach is warranted to assess supervised ML outcomes and forms the rationale for this study. This study aims to demonstrate how the item response theory (IRT) can be used to stratify the data based on how difficult each case is to classify, independent of the outcome measure of interest (eg, accuracy). This stratification allows the evaluation of ML classifiers to take the form of a distribution rather than a single scalar value. METHODS: Two large, public intensive care unit data sets, Medical Information Mart for Intensive Care III and electronic intensive care unit, were used to showcase this method in predicting mortality. For each data set, a balanced sample (n=8078 and n=21,940, respectively) and an imbalanced sample (n=12,117 and n=32,910, respectively) were drawn. A 2-parameter logistic model was used to provide scores for each case. Several ML algorithms were used in the demonstration to classify cases based on their health-related features: logistic regression, linear discriminant analysis, K-nearest neighbors, decision tree, naive Bayes, and a neural network. Generalized linear mixed model analyses were used to assess the effects of case difficulty strata, ML algorithm, and the interaction between them in predicting accuracy. RESULTS: The results showed significant effects (P<.001) for case difficulty strata, ML algorithm, and their interaction in predicting accuracy and illustrated that all classifiers performed better with easier-to-classify cases and that overall the neural network performed best. Significant interactions suggest that cases that fall in the most arduous strata should be handled by logistic regression, linear discriminant analysis, decision tree, or neural network but not by naive Bayes or K-nearest neighbors. Conventional metrics for ML classification have been reported for methodological comparison. CONCLUSIONS: This demonstration shows that using the IRT is a viable method for understanding the data that are provided to ML algorithms, independent of outcome measures, and highlights how well classifiers differentiate cases of varying difficulty. This method explains which features are indicative of healthy states and why. It enables end users to tailor the classifier that is appropriate to the difficulty level of the patient for personalized medicine.

Perceptions of effective leadership in a medical school context.

BACKGROUND: There have been calls for the development of leadership attributes in healthcare practitioners through leadership development programs. However, understanding how leadership is conceptualized is needed to assure effective participant-centred leadership development programs. The purpose of this study was to elucidate how the construct of leadership is conceptualized by multiple stakeholder groups associated with medical school leadership programs. METHODS: We conducted a total of 77 semi-structured interviews with six major demographic groups: Trainees (n = 16), Mid-Level University Leaders (n = 10), Clinician Leaders (n = 17), Senior University Leaders (n = 10), Medical Scientists (n = 12), and Senior Leaders, external to the University (n = 12) to address the research question. RESULTS: Content analyses revealed that the leaders were expected to create a compelling vision and a foster a motivating culture within the organization. Integrity and a sense of passion about leading were viewed as being principal characteristics of a leader. The twin skills of technical competence and communication were endorsed as most important for a leader. Finally, leaders are expected to be accountable for outcomes. CONCLUSION: Medical school leadership training programs should strive to incorporate these characteristics, given their broad appeal to diverse interest groups.

Short form version of the Quality of Trauma Care Patient-Reported Experience Measure (SF QTAC-PREM).

OBJECTIVE: To enable the valid and reliable measurement of patient experiences we previously published a multicenter multi-center validation of the Quality of Trauma Care Patient-Reported Experience Measure (QTAC-PREM). The purpose of this study was to derive a simplified, short form version of the QTAC-PREM to further enhance the feasibility of measuring patient experiences in injury care. To identify candidate items for the short form we reviewed the results of the original multi-center long form validation cohort study, which included 400 injury care patients and their family members recruited from three trauma centers. We only included the best performing items on the revised short form. RESULTS: The acute care component of the measure was shortened by 30% and the post-acute care component was shortened by 42%. We identified two subscales on the acute measure (information and communication; clinical and ancillary care) and one subscale on the post-acute measure (post-discharge information and communication). The measurement properties of the short form measure were similar to that of the validated long form. This short form assessment of patient injury care experiences offers a useful, practical, and easy tool for trauma centers to implement for service evaluation, quality improvement, and injury care research.

Barriers and enablers to academic health leadership.

Purpose This study sought to identify the barriers and enablers to leadership enactment in academic health-care settings. Design/methodology/approach Semi-structured interviews ( n = 77) with programme stakeholders (medical school trainees, university leaders, clinical leaders, medical scientists and directors external to the medical school) were conducted, and the responses content-analysed. Findings Both contextual and individual factors were identified as playing a role in affecting academic health leadership enactment that has an impact on programme development, success and maintenance. Contextual factors included sufficient resources allocated to the programme, opportunities for learners to practise leadership skills, a competent team around the leader once that person is in place, clear expectations for the leader and a culture that fosters open communication. Contextual barriers included highly bureaucratic structures, fear-of-failure and non-trusting cultures and inappropriate performance systems. Programmes were advised to select participants based on self-awareness, strong communication skills and an innovative thinking style. Filling specific knowledge and skill gaps, particularly for those not trained in medical school, was viewed as essential. Ineffective decision-making styles and tendencies to get involved in day-to-day activities were barriers to the development of academic health leaders. Originality/value Programmes designed to develop academic health-care leaders will be most effective if they develop leadership at all levels; ensure that the organisation's culture, structure and processes reinforce positive leadership practices; and recognise the critical role of teams in supporting its leaders.

Multicenter validation of the Quality of Trauma Care Patient-Reported Experience Measure (QTAC-PREM).

BACKGROUND: Incorporating patient and family perspectives into injury care quality assessment is a necessary part of comprehensive quality improvement. However, tools to measure patient and family perspectives of injury care are lacking. Therefore, our objective was to assess the psychometric properties of the Quality of Trauma Care Patient-Reported Experience Measure (QTAC-PREM), the first measure developed to assess patient experiences with overall injury care. METHODS: We conducted a prospective multicenter cohort study of adult injury patients recruited from three trauma centers. Patients or surrogates completed an acute care survey measure in the hospital and a post-acute care survey measure after hospital discharge. RESULTS: Four hundred participants (78%) completed the acute care measure, and 207 (59%) completed the post-acute care measure. We identified three subscales on the acute measure and two subscales on the post-acute measure. All subscales and items had evidence of construct validity. Four subscales had good internal consistency, and three were independent predictors of participants' overall ratings of injury care quality. The majority of items demonstrated suitable test-retest reliability. Comparison of QTAC-PREM scores with those of an existing patient experience tool, the Hospital version of the Consumer Assessment of Healthcare Providers and Systems (HCAHPS), demonstrated evidence of appropriate divergent and convergent validity. CONCLUSION: This study demonstrates that the QTAC-PREM is feasible to implement at trauma centers and provides evidence of validity and reliability. The tool may be useful to incorporate patient perspectives into trauma care quality measurement and improvement.

Facilitating a just and trusting culture.

PURPOSE: The purpose of this paper is to identify managerial and organizational characteristics and behaviors that facilitate the fostering of a just and trusting culture within the healthcare system. DESIGN/METHODOLOGY/APPROACH: Two studies were conducted. The initial qualitative one was used to identify themes based on interviews with health care workers that facilitate a just and trusting culture. The quantitative one used a policy-capturing design to determine which factors were most likely to predict outcomes of manager and organizational trust. FINDINGS: The factors of violation type (ability vs integrity), providing an explanation or not, blame vs no blame by manager, and blame vs no blame by organization were all significant predictors of perceptions of trust. RESEARCH LIMITATIONS/IMPLICATIONS: Limitations to the generalizability of findings included both a small and non-representative sample from one health care region. PRACTICAL IMPLICATIONS: The present findings can be useful in developing training systems for managers and organizational executive teams for managing medical error events in a manner that will help develop a just and trusting culture. SOCIAL IMPLICATIONS: A just and trusting culture should enhance the likelihood of reporting medical errors. Improved reporting, in turn, should enhance patient safety. ORIGINALITY/VALUE: This is the first field study experimentally manipulating aspects of organizational trust within the health care sector. The use of policy-capturing is a unique feature that sheds light into the decision-making of health care workers as to the efficaciousness of particular managerial and organizational characteristics that impact a just and trusting culture.

The use of cognitive interviews to revise the Quality of Trauma Care Patient-Reported Experience Measure (QTAC-PREM).

PURPOSE: The "Quality of Trauma Care Patient-Reported Experience Measure" is the first measure of patient experiences with overall injury care. The objective of this study was to use cognitive interviews to inform revision of the measure into a parsimonious set of items that function as intended, in preparation for multicenter testing. METHODS: Concurrent and retrospective cognitive interviews with injured patients (n = 17) and family members (n = 13) using semi-structured interview guides. Responses were analyzed using thematic analysis. RESULTS: Six broad themes were identified and guided revisions: (1) participants did not have the information to answer items (n = 9); (2) items were ambiguous or were inconsistently interpreted (n = 13); (3) items did not measure the intended constructs (n = 6); (4) items included assumptions about healthcare processes (n = 4); (5) items measured non-priority aspects of injury care (n = 8); and (6) items were redundant (n = 5). Two issues resulted in key conceptual and content changes: participants' difficulty to evaluate pre-hospital, emergency department, and intensive care unit services due to recall issues and the challenge to evaluate the effectiveness and equity of care. In total, 39 items were deleted, 28 new items developed, and the final instrument included 63 items. CONCLUSIONS: Our results informed changes to item content, format, and response options. This study highlights key issues to consider when incorporating patient/family perspectives into quality measurement, most notably, that few participants can assess the quality of care in the pre-hospital and emergency department phases of care and that novel methods are needed to evaluate the effectiveness and equity of care.

Prospective cohort study protocol to evaluate the validity and reliability of the Quality of Trauma Care Patient-Reported Experience Measure (QTAC-PREM).

BACKGROUND: Patient-centeredness is a key component of health care quality. However, patient-centered measures of quality have not been developed in injury care. In response to this challenge, we developed the Quality of Trauma Adult Care Patient-Reported Experience Measure (QTAC-PREM) to measure injured patient experiences with trauma care and pilot-tested the instrument at a single Level 1 trauma centre. The objective of this study is to test the reliability, validity, and feasibility of the QTAC-PREM in multiple Canadian trauma centers and to refine the measure based on the results. METHODS/DESIGN: This will be a prospective cohort study of consecutive adult (age ≥ 18 years) patients discharged from three trauma centres in Alberta, Canada with a primary diagnosis of injury. The target sample size is 400 participants to ensure precision for evaluating test-retest reliability. We will assess the psychometric properties of the measure (test-retest reliability, construct validity, internal consistency) and whether these properties vary by patient characteristics. We will also evaluate the predictive validity, convergent validity, and discriminant validity of the measure against other established tools (HCAHPS). DISCUSSION: A reliable and valid measure of patient reported experiences with injury care may be a valuable tool to evaluate quality of care and guide improvement efforts.

He said, she said: work, biopsychosocial, and lifestyle contributions to coronary heart disease risk.

OBJECTIVE: To test a model incorporating job characteristics, biopsychosocial, lifestyle, and nonmodifiable factors as they relate to coronary heart disease (CHD). Specifically, job characteristics and nonwork social ties (NWST) were examined as predictors of biopsychosocial health (BPSH), which was, in turn, expected to predict CHD directly and indirectly through influencing lifestyle. We also examined how age and family history of premature heart disease predicted objectively measured CHD risk. Within this model, sex differences were explored. METHOD: A structural equation modeling analysis of data from a cross-sectional sample of 541 employees (317 men and 224 women) taking part in a cross-organization workplace wellness program. T tests of sex differences were also conducted. RESULTS: Positive perceptions of job characteristics and NWST predicted positive BPSH. BPSH displayed no direct relationship to CHD risk, but positively predicted a healthier lifestyle. A healthier lifestyle was related to lower levels of CHD risk. Family history, but not age, was also useful in predicting CHD risk. Analyses indicated that men were significantly worse on all objective measures of CHD risk factors, but no other main effect sex differences were found. There were no differences between men and women in the relationships between variables. CONCLUSIONS: Adds to a body of literature indicating the importance of psychological components of the job in determining biopsychosocial health, and the importance of this variable in its impact on lifestyle decisions. The results support continued efforts to guide future interventions on lifestyle for both men and women.

Social workers and satisfaction with child welfare work: aspects of work, profession, and personal life that contribute to turnover.

Social workers practicing in government-mandated child welfare programs experience several unique challenges and workplace stressors that can contribute to social worker workplace dissatisfaction and higher rates of turnover. Most research on workplace wellbeing primarily focuses on workplace characteristics rather than on other variables, such as personal and professional life factors. From a sample of child welfare workers (n = 145), and following a model of subjective well-being, our findings show that three factors--work, profession, and personal life--significantly predict overall social worker satisfaction and intention to leave, confirming previous research on the multiple aspects of a social worker's life that contributes to his or her subjective well-being.

Scale validation via quantifying item validity using the Dm index.

While most validity indices are based on total test scores, this paper describes a method for quantifying the construct validity of items. The approach is based on the item selection technique originally described by Piazza in 1980. Unfortunately, Piazza's P2 index suffers from some substantial limitations. The Dm coefficient provides an alternative which can be used for item selection and provides a validity index for a set of items. The index is similar to that of traditional criterion-related validity indices. Criterion-related validity is used to demonstrate the accuracy of hypothesized relations of the measure with outcome variables of interest in research and practice. This method may be useful when the sample of items or persons is small, rendering more traditional approaches such as factor analysis or item response theory inappropriate. An example of how to use the technique is provided.

Determinants of adverse events in hospitals--the potential role of patient safety culture.

This study investigated two contributing factors in predicting adverse events in hospital settings. We approached this issue using the statistical procedure of hierarchical linear modeling to test for multilevel relationships. We found that the resource intensity of the presenting case was related to the severity level of negative incidents in hospital settings in a large metropolitan center. More important, we found that a more positive culture of patient safety within hospital units was related to lower incident severity. More than 8,000 admissions within 40 different units in three hospitals were included in the analyses.