Journey across epidemiology's third variables: an anesthesiologist's guide for successfully navigating confounding, mediation, and effect modification

Observational clinical research studies aim to assess which exposures (treatments or other factors; independent variable) affect patient outcomes (dependent variable). These exposures include medical interventions in situations where clinical trials are not possible or prior to their conduct and completion. However, the assessment of the relationship between exposures and outcomes is not straightforward, as other variables may need to be considered prior to reaching valid conclusions. Here, we present three hypothetical scenarios in regional anesthesia to review the epidemiological concepts of confounding, mediation, and effect modification. Understanding these concepts is critical for assessing the design, analysis, and interpretation of clinical studies. These terms may be confusing to anesthesiologists and researchers alike, where such confusion could affect the conclusions of a clinical study, mislead the target audience, and ultimately impact patient health.

Clinical, developmental and molecular update on Cornelia de Lange syndrome and the cohesin complex: abstracts from the 2014 Scientific and Educational Symposium

Cornelia de Lange Syndrome (CdLS) is the most common example of disorders of the cohesin complex, or cohesinopathies. There are a myriad of clinical issues facing individuals with CdLS, particularly in the neurodevelopmental system, which also have implications for the parents and caretakers, involved professionals, therapists, and schools. Basic research in developmental and cell biology on cohesin is showing significant progress, with improved understanding of the mechanisms and the possibility of potential therapeutics. The following abstracts are presentations from the 6th Cornelia de Lange Syndrome Scientific and Educational Symposium, which took place on June 25-26, 2014, in conjunction with the Cornelia de Lange Syndrome Foundation National Meeting in Costa Mesa, CA. The Research Committee of the CdLS Foundation organizes the meeting, reviews and accepts abstracts, and subsequently disseminates the information to the families through members of the Clinical Advisory Board. In addition to the scientific and clinical discussions, there were educationally focused talks related to practical aspects of behavior and development. AMA CME credits were provided by Greater Baltimore Medical Center, Baltimore, MD.

Anesthetic implications of undiagnosed late onset central hypoventilation syndrome in a child: from elective tonsillectomy to tracheostomy

Late onset central hypoventilation syndrome is a neurological disorder that can present with postoperative respiratory complications and delayed emergence in children after anesthesia. We present a child who had unanticipated respiratory complications following an elective tonsillectomy who eventually required a tracheostomy and long-term ventilatory support.

Sedation and fiberoptic intubation of a neonate with a cystic hygroma

The flexible bronchoscope (FB) has been used to secure the difficult airway in pediatric patients. Difficult intubations in patients with cystic hygromas have been performed in awake patients or after the induction of general anesthesia. A recent case report acknowledges the challenges of performing intubations in pediatric patients under sedation because of their inability to fully cooperate. The following case demonstrates the two step-two fiberoptic bronchoscopic tracheal intubation performed using sedation and topical anesthesia in a neonate with a difficult airway.

Establishing reliability and validity of the critical care family satisfaction survey

OBJECTIVE

To develop and validate the Critical Care Family Satisfaction Survey as a proxy for patient satisfaction.

DESIGN

Instrument validation study. SETTING AND TIME FRAME: The Medical Intensive Care, Shock Trauma, Acute Coronary Care, Central Nervous System, Surgical Intensive Care, and Special Care units of Lehigh Valley Hospital (Allentown, PA), for the period December 1997 through September 1998.

PATIENTS/PARTICIPANTS

One family member for each of 237 critical care patients.

INTERVENTION(S)

Content and construct validity were examined on 37 items and 6 constructs thought to measure family satisfaction with the quality of critical care in hospitals. Initially, 14 items and 1 construct were removed from the questionnaire based on this analysis. It was then administered to 237 family members.

MEASUREMENTS AND MAIN RESULTS

Factor analysis and confirmatory factor analysis using path models were performed. Internal consistency using Pearson correlations and Cronbach's alpha, and discriminant validation were also calculated. Factor analysis yielded a single eigenvalue >1 (3.712), whereas confirmatory factor analysis led to the final instrument being reduced to 20 items and 5 subscale constructs. One subscale ("Comfort") performed poorly, indicating the possible need for a four-factor model. Subsequently, internal consistency assessed by Cronbach's alpha was 0.9101 for the five-factor model and 0.9327 for the four-factor model. Subscale correlations were no lower than 0.750 for the five-factor model and 0.856 for the four-factor model.

CONCLUSIONS

This study provides support that the Critical Care Family Satisfaction Survey-which yields five subscales, "Assurance," "Information," "Proximity," "Support," and "Comfort"--is reliable and valid. Using five constructs rather than four is recommended because of the following: a) the internal consistency loss of 0.0226 for the "Comfort" subscale is not enough to warrant its removal, b) a four-factor questionnaire can be administered and totaled independently of this subscale, c) the need for the fifth construct is indicated by this study's results, and d) including the extra data may allow for more detailed analysis.

Longitudinal nursing case management for elderly heart failure patients: notes from the field

Longitudinal case management is an intervention delivered by professional nurses that involves following patients from the inpatient to the outpatient arena. The hands-on process of day-to-day case management of elderly persons with heart failure is presented. The issues associated with delivering this intervention to this patient population are examined, and implications for refining the case management process are discussed.

Changing clinical practice through research: the case of delirium

Promoting application of study findings to the clinical setting is a constant challenge for nurse researchers. This project used change theory to include staff RNs in a research study on delirium and to use relevant findings. The research hypothesis was: Staff nurses who use a standardized protocol will have improved ability to identify delirium in elderly hospital patients. Staff nurses on the intervention unit used this protocol to screen for delirium on all consenting inpatients 75 years of age and over, and control unit nurses continued using their standard assessment practices. Intervention unit nurses demonstrated an improved ability to identify the presence and absence of delirium, and voluntarily requested to continue using the protocol after the study was terminated. Use of a theoretical model to include nurses in the study promoted the successful conduct of the research and subsequent use of findings.

Partners in care: a model of collaboration

It is estimated that 3 million persons in the United States have congestive heart failure. This diagnosis accounts for more than 5% of total health expenditures. A method to decrease the costs of health care was initiated through the partners-in-care model of collaborative practice. A research study exploring the use of nurse case managers in collaboration with cardiologists and primary care physicians is being conducted with persons older than 65 years. This care encompasses both inpatient and outpatient care. The intervention comprises nurse visits in the hospital and in the home as well as telephone support for 6 months after the index hospitalization. The outcomes of quality of life, functional status, mortality, morbidity, and costs are being examined. Collaborative health care partnerships may be an effective strategy to decrease health care costs and improve quality of life and functional status of older persons with congestive heart failure.

Nurses preparing for change: their needs and concerns

As a result of decreased lengths of stay and cost-containment initiatives, fewer nurses are needed in acute care settings. The trend for community-based health care is broadening employment opportunities for nurses to work in community settings. As nurses are considering options to base their practice in community settings, it is important to understand their concerns about making this transition. The results of a qualitative study conducted to examine the concerns and educational needs of acute care nurses related to working in the community are reported. Clinical, professional, and intrapersonal skills important for a successful transition to community-based practice are identified and discussed.