Hot-deck imputation is an intuitively simple and popular method of accommodating incomplete data. Users of the method will often use the usual multiple imputation variance estimator which is not appropriate in this case. However, no variance expression has yet been derived for this easily implemented method applied to missing covariates in regression models. The simple hot-deck method is in fact asymptotically equivalent to the mean-score method for the estimation of a regression model parameter, so that hot-deck can be understood in the context of likelihood methods. Both of these methods accommodate data where missingness may depend on the observed variables but not on the unobserved value of the incomplete covariate, that is, missing at random (MAR). The asymptotic properties of hot-deck are derived here for the case where the fully observed variables are categorical, though the incomplete covariate(s) may be continuous. Simulation studies indicate that the two methods compare well in small samples and for small numbers of imputations. Current users of hot-deck may now conduct their analysis using mean-score, which is a weighted likelihood method and can thus be implemented by a single pass through the data using any standard package which accommodates weighted regression models. Valid inference is now straightforward using the variance expression provided here. The equivalence of mean-score and hot-deck is illustrated using three clinical data sets where an important covariate is missing for a large number of study subjects.

Angioplasty, Balloon, Coronary↗

PubMedDate not supplied

Is CT angiography sufficient for prediction of resectability of periampullary neoplasms?

The optimal preoperative evaluation of periampullary neoplasms remains controversial. The aim of this study was to analyze the accuracy of helical computed tomography (CT) and CT angiography with three-dimensional reconstruction in predicting resectability. Between March 1996 and May 1999, a total of 100 patients with periampullary neoplasms were prospectively staged by helical CT and CT angiography with three-dimensional reconstruction. Vascular involvement was graded from 0 to 4, with grade 0 representing no vascular involvement and grade 4 total encasement of either the superior mesenteric vein or artery. Patients with grade 4 lesions were considered unresectable. Sixty-eight patients underwent surgical exploration with intent to perform a pancreaticoduodenectomy. Forty-four lesions were grade 0, five were grade l, eight were grade 2, and 11 were grade 3. Resectability for grades 0 to 3 was 96%, 100%, 50%, and 9%, respectively, for an overall resectability rate of 76%. Resectability in patients with vascular encroachment (grade 2) is usually determined by the extent of local disease rather than the presence of extrapancreatic disease. Resection is rarely possible in patients with evidence of vascular encasement (grade 3). Additional imaging modalities such as diagnostic laparoscopy are superfluous in patients with no evidence of local vascular involvement on CT angiography (grades 0 and 1) because of the high resectability rate and infrequency of unsuspected distant metastatic deposits.

Adenoma↗

PubMedDate not supplied

Therapeutic leukapheresis in a patient with hairy cell leukemia presenting with a white cell count greater than 500,000 /microliter.

A 49-year-old man presented with anemia, thrombocytopenia, and white cell count over 500,000 /microliters. Studies were diagnostic of hairy cell leukemia. Splenectomy was considered hazardous because of his general poor condition and the danger of leukostasis from the high white cell count. He was managed with leukapheresis with reduction in the white cell count from 556,000 /microliters to 20,000 /microliters followed by an uneventful splenectomy. Leukapheresis should be considered for patients with hairy cell leukemia and extremely elevated white cell counts.

Humans↗

PubMedDate not supplied

Needs assessment of homebound elders in a parish church: implications for parish nursing.

The goals in managing chronic illnesses in the elderly are to maintain the highest possible level of functioning, promote independence in self-care, and enhance quality of life. Parish nursing is one mechanism for providing care for homebound elders with one or more chronic illnesses. However, determining the holistic health needs of older parishioners before developing a parish nursing program is helpful. The holistic needs of elders in two parishes were determined through two multidimensional functional assessment questionnaires and a quality of life scale. Results indicate that this population of elders had relatively high levels of functioning. Quality of life was relatively high and was associated with overall functional abilities.

Activities of Daily Living↗

PubMedDate not supplied

The modernization of occupational therapy.

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Community Health Services↗