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Miskulin, D.C., Meyer, K.B., Athienites, N.V., and others (2002, February). "Comorbidity and other factors associated with modality selection in incident dialysis patients: The CHOICE Study." (AHRQ grant HS08365). American Journal of Kidney Diseases 39(2), pp. 324-336.

The increased survival of peritoneal dialysis (PD) patients reported in recent studies may simply reflect the self- or physician-directed selection of healthier patients to PD, according to this study. The authors assert that case-mix factors influence both the selection of dialysis modality and outcomes in patients with end-stage renal disease (ESRD). They compared the baseline characteristics of 279 PD and 750 hemodialysis (HD) patients. The number and severity of coexisting medical conditions at the onset of ESRD were significantly lower in patients choosing PD, independent of other factors influencing selection of dialysis type. The authors conclude that adjustment for case-mix differences in patients treated with PD versus HD is essential to the assessment of the independent effects of the dialysis modality on outcomes.

Patrician, P.A. (2002). "Focus on research methods: Multiple imputation for missing data." (AHRQ grant HS08603). Research in Nursing & Health 25, pp. 75-84.

Missing data poses a problem in survey and longitudinal research. In surveys, individuals may not respond to certain questions for a variety of reasons. In longitudinal studies, participants relocate, die, or drop out for other reasons. Recent theoretical and computational advances, most notably multiple imputation methods, enable the researcher to use the existing data to generate, or impute, values approximating the "real" value, while preserving the uncertainty of the missing values. This article reviews the problems associated with missing data, options for handling missing data, and recent multiple imputation methods. It informs researchers' decisions about whether to delete or impute missing responses and the method best suited to doing so. The authors use an empirical investigation of AIDS care data to illustrate the process of multiple imputation.

Sherman, K.J., Hogeboom, C.J., Cherkin, D.C., and Deyo, R.A. (2002). "Description and validation of a noninvasive placebo acupuncture procedure." (AHRQ grant HS09989). Journal of Alternative and Complementary Medicine 8(1), pp. 11-19.

This study found that using a toothpick inside a guidetube (to hide the toothpick) to "poke" a person is a reasonable control treatment for acupuncture-naive individuals in trials assessing the efficacy of acupuncture for low back pain. In the first experiment, a group of low back pain patients received six insertions of needles while another group received six pokes with a toothpick in a guidetube. Then the groups were switched. In the second experiment, low back pain patients were randomly assigned to receive either a complete treatment with real acupuncture needles or a simulated treatment using a toothpick in a guidetube. In the first experiment, the toothpick insertions were perceived as slightly more like real needling than the real needling. In the second experiment, 52 percent of those receiving the simulated needling versus 65 percent of those receiving real acupuncture believed they were "definitely" or "probably" receiving real acupuncture.

Weinger, M.B., and Ancoli-Israel, S. (2002, February 27). "Sleep deprivation and clinical performance." (AHRQ grants HS11521 and HS11375). Journal of the American Medical Association 287(8), pp. 955-957.

In this study of sleep deprivation and clinical performance, researchers reviewed laboratory and clinical studies and found that patient care may be compromised if a fatigued, sleep-deprived doctor is allowed to operate, administer an anesthetic, manage a medical crisis, or deal with an unusual or cognitively demanding clinical case. Two meta-analyses of recent laboratory studies revealed that sleep-deprived people performed well below those who were not sleep-deprived. Sleep deprivation had the greatest impact on mood and cognitive tasks and less, but still significant, impact on motor tasks. Clinical studies found that sleep-deprived medical interns detected fewer cardiac arrhythmias and complained of feeling sad, fatigued, and unsure of themselves when compared with rested interns. Compared with well-rested surgical residents, those deprived of sleep all night or due to on-call interruptions made more errors and were slower to complete electrocoagulation of bleeding tissue in a virtual reality simulation of laparoscopic surgery. One study found that sleep-deprived anesthesiologists needed more time to monitor patient physiology, a routine clinical task, while another found that some of them fell asleep while administering anesthesia in a simulated surgery.

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Current as of June 2002
AHRQ Publication No. 02-0032

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