Tutorials in clinical research: part III. Selecting a research approach to best answer a clinical question.

OBJECTIVE: This is the third in a series of sequential "Tutorials in Clinical Research." The objectives of this specific report are to enable the reader to rapidly dissect a clinical question or article to efficiently determine what critical mass of information is required to answer the question and what study design is likely to produce the answer. STUDY DESIGN: Tutorial. METHODS: The authors met weekly for 3 months exploring clinical problems and systematically recording the logic and procedural pathways from multiple clinical questions to the selection of proper research approaches. The basic elements required to understand the processes of selection were catalogued and field tested, and a report was produced to define and explain these elements. RESULTS: Fundamental to a research approach is the assembly of subjects and the allocation of exposures. An algorithm leading to the selection of an approach is presented. The report is organized into three parts. The tables serve as a rapid reference section. The initial two-part narrative explains the process of approach selection. The examples section illustrates the application of the selection algorithm. CONCLUSIONS: Selecting the proper research approach has six steps: the question, logic and ethics,identification of variables, data display considerations, original data source considerations, and selection of prototypical approaches for assembly of subjects. Field tests of this approach consistently demonstrated its utility.

Free jejunal graft: effects of longitudinal myotomy.

Pharyngoesophageal reconstruction using the free vascularized jejunal graft results in dysphagia in approximately 20% to 40% of patients. This may be caused by graft contractility, and we therefore developed this canine model to assess the functional effects of myotomy on transplanted jejunum. Nine female dogs underwent microvascular transposition of jejunum to the neck, the bowel being placed subcutaneously with two end jejunostomies. Baseline functional manometry was performed. Five animals then underwent complete longitudinal myotomy and four animals underwent a sham procedure. Graft function was then reevaluated after complete would healing. Contraction frequency, contraction amplitude, and total work done by the graft were recorded; all grafts demonstrated activity and were more active postrecovery than at the time of operation. Although myotomy animals showed a within-group trend to decreased contractility postintervention, this was not statistically significant. Furthermore, there was no significant postintervention difference between the sham and myotomy groups. We conclude that our model is effective for the study of activity in the free jejunal graft and that longitudinal myotomy does not significantly reduce, let alone ablate contraction.

Hair relaxer ingestion: a new trend.

Although the health care system has done much to reduce the incidence of ingestion of such alkalis as drain and oven cleaners, in recent years we have seen an overwhelming increase in the incidence of hair relaxer ingestion. In a 5-year review (1987 to 1992) of 48 cases of caustic ingestion, 15 cases involved alkaline hair-relaxing agents. This retrospective study was undertaken to evaluate the agents ingested, the presenting signs and symptoms, the diagnostic procedures, and the outcomes in those 15 cases. Oral cavity and lip burns were common in these children, but none of the 15 had significant esophageal burns. Education of the medical and lay community about the risk of hair relaxer ingestion should be undertaken to reverse this worrisome trend.

Lipofibromatosis presenting as a pediatric neck mass.

Lipofibromatosis is a recently described, benign neoplasm that presents in the pediatric population [J.F. Fetsch, M. Miettinen, W.B. Laskin, M. Michal, F.M. Enzinger, A clinicopathologic study of 45 pediatric soft tissue tumors with an admixture of adipose tissue and fibroblastic elements, and a proposal for classification as lipofibromatosis, Am. J. Surg. Pathol. 24 (2000) 1491-1500]. It is a rare soft tissue tumor histologically distinct from other fibromatoses such as juvenile fibromatosis, fibrous hamartoma of infancy, calcifying aponeurotic fibroma, and lipoblastoma. Distinguishing histopathologic features of lipofibromatosis include abundant and disorganized adipose lobules traversed by bundles of spindled fibroblast-like cells. It most commonly presents in the extremities. We present a case involving a young girl, which we believe represents the first report of lipofibromatosis involving the neck.