Summary Hot deck imputation is a method for handling missing data in which each missing value is replaced with an observed response from a “similar” unit. Despite being used extensively in practice, the theory is not as well developed as that of other imputation methods. We have found that no consensus exists as to the best way to apply the hot deck and obtain inferences from the completed data set. Here we review different forms of the hot deck and existing research on its statistical properties. We describe applications of the hot deck currently in use, including the U.S. Census Bureau’s hot deck for the Current Population Survey (CPS). We also provide an extended example of variations of the hot deck applied to the third National Health and Nutrition Examination Survey (NHANES III). Some potential areas for future research are highlighted.

Purpose To evaluate yoga's impact on inflammation, mood, and fatigue. Patients and Methods A randomized controlled 3-month trial was conducted with two post-treatment assessments of 200 breast cancer survivors assigned to either 12 weeks of 90-minute twice per week hatha yoga classes or a wait-list control. The main outcome measures were lipopolysaccharide-stimulated production of proinflammatory cytokines interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and interleukin-1β (IL-1β), and scores on the Multidimensional Fatigue Symptom Inventory-Short Form (MFSI-SF), the vitality scale from the Medical Outcomes Study 36-item Short Form (SF-36), and the Center for Epidemiological Studies-Depression (CES-D) scale. Results Immediately post-treatment, fatigue was not lower (P > .05) but vitality was higher (P = .01) in the yoga group compared with the control group. At 3 months post-treatment, fatigue was lower in the yoga group (P = .002), vitality was higher (P = .01), and IL-6 (P = .027), TNF-α (P = .027), and IL-1β (P = .037) were lower for yoga participants compared with the control group. Groups did not differ on depression at either time (P > .2). Planned secondary analyses showed that the frequency of yoga practice had stronger associations with fatigue at both post-treatment visits (P = .019; P < .001), as well as vitality (P = .016; P = .0045), but not depression (P > .05) than simple group assignment; more frequent practice produced larger changes. At 3 months post-treatment, increasing yoga practice also led to a decrease in IL-6 (P = .01) and IL-1β (P = .03) production but not in TNF-α production (P > .05). Conclusion Chronic inflammation may fuel declines in physical function leading to frailty and disability. If yoga dampens or limits both fatigue and inflammation, then regular practice could have substantial health benefits.

Using Surveillance, Epidemiology and End Results cancer registry data, we assessed survival after breast cancer diagnosis among women diagnosed during 2010 to 2013 and followed through December 31, 2014. Breast cancer molecular subtypes defined by joint hormone receptor [HR, estrogen receptor (ER) and/or progesterone receptor (PR)] and HER2 status were assessed. Multiple imputation was used to fill in missing receptor status. Four-year breast cancer-specific survival per molecular subtypes and clinical/demographic factors were calculated. A Cox proportional hazards model was used to evaluate survival while controlling for clinical and demographic factors. The best survival pattern was observed among women with HR/HER2 subtype (survival rate of 92.5% at 4 years), followed by HR/HER2 (90.3%), HR/HER2 (82.7%), and finally worst survival for triple-negative subtype (77.0%). Notably, failing to impute cases with missing receptor status leads to overestimation of survival because those with missing receptor status tend to have worse prognostic features. Survival differed substantially by stage at diagnosis. Among stage IV disease, women with HR/HER2 subtype experienced better survival than those with HR/HER2 subtype (45.5% vs. 35.9%), even after controlling for other factors. Divergence of survival curves in stage IV HR/HER2 versus HR/HER2 subtype is likely attributable to major advances in HER2-targeted treatment. Contrary to conventional thought, HR/HER2 subtype experienced better survival than HR/HER2 in advanced-stage disease. .

Observational studies have linked lower omega-3 (n-3) polyunsaturated fatty acids (PUFAs) and higher omega-6 (n-6) PUFAs with inflammation and depression, but randomized controlled trial (RCT) data have been mixed. To determine whether n-3 decreases proinflammatory cytokine production and depressive and anxiety symptoms in healthy young adults, this parallel group, placebo-controlled, double-blind 12-week RCT compared n-3 supplementation with placebo. The participants, 68 medical students, provided serial blood samples during lower-stress periods as well as on days before an exam. The students received either n-3 (2.5 g/d, 2085 mg eicosapentaenoic acid and 348 mg docosahexanoic acid) or placebo capsules that mirrored the proportions of fatty acids in the typical American diet. Compared to controls, those students who received n-3 showed a 14% decrease in lipopolysaccharide (LPS) stimulated interleukin 6 (IL-6) production and a 20% reduction in anxiety symptoms, without significant change in depressive symptoms. Individuals differ in absorption and metabolism of n-3 PUFA supplements, as well as in adherence; accordingly, planned secondary analyses that used the plasma n-6:n-3 ratio in place of treatment group showed that decreasing n-6:n-3 ratios led to lower anxiety and reductions in stimulated IL-6 and tumor necrosis factor alpha (TNF-α) production, as well as marginal differences in serum TNF-α. These data suggest that n-3 supplementation can reduce inflammation and anxiety even among healthy young adults. The reduction in anxiety symptoms associated with n-3 supplementation provides the first evidence that n-3 may have potential anxiolytic benefits for individuals without an anxiety disorder diagnosis. ClinicalTrials.gov identifier: NCT00519779

Objective Pain, depression, and fatigue function as a symptom cluster and thus may share common risk factors. Interpersonal relationships clearly influence health, suggesting that loneliness may promote the development of the pain, depression, and fatigue symptom cluster. We hypothesized that loneliness would be related to concurrent symptom cluster levels and increases in symptom cluster levels over time. Methods We utilized two observational studies with distinct longitudinal samples. Study 1 was a sample of cancer survivors and benign controls (N=115) assessed annually for 2 years. Study 2 was a sample of older adults caring for a spouse with dementia (caregivers) and non-caregiver controls (N=229) assessed annually for 4 years. Participants completed annual measures assessing loneliness, pain, depression, and fatigue. Results Across both samples, lonelier participants experienced more concurrent pain, depression, and fatigue and larger increases in symptom cluster levels from one year to the next than less lonely participants. Sleep quality did not mediate the results in either study. All analyses were adjusted for relevant demographic and health variables. Conclusions Two longitudinal studies with different populations demonstrated that loneliness was a risk factor for the development of the pain, depression, and fatigue symptom cluster over time. The current research helps identify people most at risk for pain, depression, and fatigue, and lays the groundwork for research about their diagnosis and treatment. These data also highlight the health risks of loneliness; pain, depression, and fatigue often accompany serious illness and place people at risk for poor health and mortality.