Recommended tests for association in 2×2 tables

The asymptotic Pearson's chi‐squared test and Fisher's exact test have long been the most used for testing association in 2×2 tables. Unconditional tests preserve the significance level and generally are more powerful than Fisher's exact test for moderate to small samples, but previously were disadvantaged by being computationally demanding. This disadvantage is now moot, as software to facilitate unconditional tests has been available for years. Moreover, Fisher's exact test with mid‐p adjustment gives about the same results as an unconditional test. Consequently, several better tests are available, and the choice of a test should depend only on its merits for the application involved. Unconditional tests and the mid‐p approach ought to be used more than they now are. The traditional Fisher's exact test should practically never be used. Copyright © 2009 John Wiley & Sons, Ltd.     

Physical activity in Hodgkin's lymphoma survivors with and without chronic fatigue compared with the general population – a cross-sectional study

Background  

Hodgkin's lymphoma survivors (HLSs) commonly report chronic fatigue, defined as high levels of fatigue for 6 months or more. Underlying mechanisms are poorly understood. Based upon knowledge from other populations, lifestyle parameters may be related to this increased and persistent fatigue. The primary objective of the present study was to assess self-reported levels of physical activity, smoking habits and sleep patterns in HLSs with and without chronic fatigue. The secondary objective was to compare these results with data from age and gender adjusted data from the general population (Gen-Pop).     

The lived experience of stroke survivors with early depressive symptoms: A longitudinal perspective

Purpose

The aim of the study was to describe the lived experience as it develops over time in stroke survivors suffering from early depressive symptoms.

Method

This paper presents a phenomenological hermeneutical interview-study of nine participants at 6, 12, and 18 months after stroke.

Findings

The participants related the depressive symptoms to the consequences of the stroke, and the experience of loss was crucial. Depressive symptoms was not meaningful on its own, but formed the backdrop of the experience of stroke. Our findings revealed three patterns of experience: (1) finding a restored self; (2) trapped in a different life; and (3) fighting to regain self.Two groups of stroke survivors are particularly vulnerable and should receive special attention: (a) old adults living alone; and (b) adults experiencing serious threats to their commitments such as to work, family, and children.

Conclusion

Depressive symptoms have a severe impact on life after stroke. Life circumstances, degree of residual impairment from a stroke, and social context were found to influence people to move along different paths. Older adults living alone and adults experiencing serious threat to their commitments should receive special attention, in terms of further research and in terms of follow-up in clinical practice.More studies investigating the experience of post-stroke depression (PSD) over time and the association between depressive symptoms and loss/grieving are needed. There is also a need for continued empirical research on the identification of effective interventions aimed at prevention or improved coping with PSD.     

Long-term in-vitro precision of direct digital X-ray radiogrammetry

Objective  

Digital X-ray radiogrammetry (DXR) calculates peripheral bone mineral density (BMD) from hand radiographs. The short-term precision for direct DXR has been reported to be highly satisfactory. However, long-term precision for this method has not been examined. Thus, the aim of this study was to examine the long-term in-vitro precision for the new direct digital version of DXR.     

International comparison of the relationship of chronic kidney disease prevalence and ESRD risk

ESRD incidence is much lower in Europe compared with the United States. This study investigated whether this reflects a difference in the prevalence of earlier stages of chronic kidney disease (CKD) or other mechanisms. CKD prevalence in Norway was estimated from the population-based Health Survey of Nord-Trondelag County (HUNT II), which included 65,181 adults in 1995 through 1997 (participation rate 70.4%). Data were analyzed using the same methods as two US National Health and Nutrition Examination Surveys in 1988 through 1994 (n = 15,488) and 1999 through 2000 (n = 4101). The primary analysis used gender-specific cutoffs in estimating persistent albuminuria for CKD stages 1 and 2. ESRD rates and other relevant data were extracted from national registries. Total CKD prevalence in Norway was 10.2% (SE 0.5): CKD stage 1 (GFR >90 ml/min per 1.73 m2 and albuminuria), 2.7% (SE 0.3); stage 2 (GFR 60 to 89 ml/min per 1.73 m2 and albuminuria), 3.2% (SE 0.4); stage 3 (GFR 30 to 59 ml/min per 1.73 m2), 4.2% (SE 0.1); and stage 4 (GFR 15 to 29 ml/min per 1.73 m2), 0.2% (SE 0.01). This closely approximates reported US CKD prevalence (11.0% in 1988 through 1994 and 11.7% in 1999 through 2000). The relative risk for progression from CKD stages 3 or 4 to ESRD in US white patients compared with Norwegian patients was 2.5. This was only modestly modified by adjustment for age, gender, and diabetes. Age and GFR at start of dialysis were similar, hypertension and cardiovascular mortality in the populations were comparable, but US white patients were referred later to a nephrologist and had higher prevalence of obesity and diabetes. In conclusion, CKD prevalence in Norway was similar to that in the United States, suggesting that lower progression to ESRD rather than a smaller pool of individuals at risk accounts for the lower incidence of ESRD in Norway.     

Cytological criteria for the diagnosis of intraductal hyperplasia, ductal carcinoma in situ, and invasive carcinoma of the breast

The advent of mammography screening presents a diagnostic challenge to the cytopathologist as an increasing proportion of breast lesions requiring investigation will be nonpalpable and up to 40% will be accounted for by atypical intraductal hyperplasia and ductal carcinoma in situ, as opposed to previously, when these lesions represented less than 10% of palpable tumors. We studied 133 fine-needle aspirates from breast tumors and found that nuclear morphology, myoepithelial cells, signs of invasion, and degree of cellular dissociation are among the most potent factors discriminating between benign epithelial proliferations, atypical intraductal hyperplasia, ductal carcinoma in situ, and invasive carcinoma.