Evaluation of the XVI dual registration tool for image-guided radiotherapy in prostate cancer.

PURPOSE: To compare the reliability and the required time for two cone-beam CT (CBCT) registration methods for prostate irradiation (PI) and prostate bed irradiation (PBI). MATERIAL AND METHODS: Two-hundred treatment fractions (in 10 PI and 10 PBI patients) were reanalyzed, using two CBCT registration methods: (1) a combination of an automated chamfer matching (CM) with manual matching (MM), and (2) the automated XVI dual registration tool (DRT). Bland-Altman 95% Limits of Agreement (LoA) were used to assess agreement with manual registration by Radiation Oncologists. RESULTS: All 95% LoA for CM + MM were ≤ 0.33 cm. For DRT, several 95% LoA were notably larger than the predefined clinical threshold of 0.3 cm: -0.47 to +0.25 cm (PI) and -0.36 to +0.23 cm (PBI) for the superior-inferior direction and -0.52 to +0.24 cm (PI) and -0.38 to +0.31 cm (PBI) for the anterior-posterior direction.For PI, the average time required was 33 s with CM + MM versus only 18 s with DRT (p = 0.002). For PBI, this was 13 versus 19 s, respectively (p = 0.16). CONCLUSION: For PI, DRT was significantly faster than CM + MM, but the accuracy is insufficient to use without manual verification. Therefore, manual verification is still warranted, but could offset the time benefit. For PBI, the CM + MM method was faster and more accurate.

Healthcare seeking behaviour of students living on their own compared to those living in the parental home: a cross-sectional study.

Objective This study aimed to investigate differences in healthcare seeking behaviour and barriers between students living in the parental home and those living on their own. Participants Five hundred and six second year students of the University of Amsterdam (UvA), interviewed in March and April 2015. Methods In a paper-and-pencil survey, questions were asked about the students' healthcare seeking behaviour and barriers. Differences according to residency were analysed with χ2-tests and regression models. Results The frequency of healthcare seeking behaviour varied according to residency, but none of the differences were statistically significant. Yet, a proportion of students living on their own visited primary healthcare providers less often after they changed residency (23.7% for general practitioner and 41.8% for dentist). Travel distance and lack of time were most often mentioned as barriers to students living on their own. Conclusion The barriers implicate the importance of encouraging students living on their own to switch to a new general practitioner or dentist.

How economic recessions and unemployment affect illegal drug use: A systematic realist literature review.

BACKGROUND: Economic recessions may influence illegal drug use via different mechanisms, for example increased use due to more psychological distress or decreased use due to lower incomes and purchasing power. This paper reviews the literature on how economic recessions and unemployment affect the use of illegal drugs among adults. METHODS: We conducted a systematic realist literature review, which is an explanatory method that aims to understand underlying mechanisms that connect an event to an outcome in a specific context. A systematic search was performed in EconLit, Embase, Medline, PsycINFO, SocIndex, and Web of Science for studies examining mechanisms explaining how recessions or unemployment affect illegal drug use. RESULTS: We synthesized 28 studies published between 1990 and 2015. Most evidence (17 studies) was found for the counter-cyclical mechanism that recessions and unemployment increase psychological distress, which increases drug use. Mainly supportive evidence for this mechanism was found in several high quality studies, in different contexts, and in a diverse number of countries and samples. In contrast, decreased income did not seem to decrease drug use (10 studies). Little evidence was available on the non-working time mechanism (4 studies) and the social exclusion mechanism (5 studies). Most of the studies that did examine these latter mechanisms confirmed the hypothesized counter-cyclical associations. CONCLUSION: The current evidence is in line with the hypothesis that drug use increases in times of recession because unemployment increases psychological distress which increases drug use. During times of recession, psychological support for those who lost their job and are vulnerable to drug use (relapse) is likely to be important.

Stronger declines in youth alcohol consumption thanks to stronger integrated alcohol policies? A qualitative comparison of ten Dutch municipalities.

BACKGROUND: Little detailed evidence is available on how integrated policies could impact population health and under what conditions such policies could be realized. The aim of this study was to assess how youth alcohol consumption trends in the province of Noord-Brabant, The Netherlands, were related to the development and implementation of integrated policies. METHODS: In a retrospective multiple case study, alcohol policies of six municipalities with stronger declines in youth alcohol consumption between 2007 and 2011 (cases) were compared to four municipalities with weaker declines (controls). Information on the policy process in the same period was obtained through semi-structured in-depth interviews with policy advisors. Information on implemented interventions was extracted from policy documents and checked by the interviewees. Interviews were analyzed for thematic content. RESULTS: Only municipalities with stronger declines in alcohol consumption involved sectors other than public health and had started to implement interventions that use regulatory or enforcement strategies. Their involvement was facilitated by framing youth alcohol consumption as a safety rather than a health problem, whereby local media played a substantial role. Implementation of integrated policies was further facilitated by dedicated leadership and sufficient resources. CONCLUSIONS: Reductions in youth alcohol consumption in Noord-Brabant were stronger when municipalities started to develop integrated policies. Results suggest that integrated policies framing a health problem as a broader societal problem could positively influence population health.

Harmful drinking after job loss: a stronger association during the post-2008 economic crisis?

OBJECTIVES: This study investigated, among the Dutch working population, whether job loss during the post-2008 economic crisis is associated with harmful drinking and whether this association is stronger than before the crisis. METHODS: Repeated cross-sectional data from the Dutch Health Interview Survey 2004-2013 were used to define episodic drinking (≥6 glasses on 1 day ≥1/week) and chronic drinking (≥14 glasses/week for women and ≥21 for men). These data were linked to longitudinal data from tax registries, to measure the experience and duration of job loss during a 5-year working history. RESULTS: Before the crisis, job loss experience and duration were not associated with harmful drinking. During the crisis, job loss for more than 6 months was associated with episodic drinking [OR 1.40 (95% CI 1.01; 1.94)], while current job loss was associated with chronic drinking [OR 1.43 (95% CI 1.03; 1.98)]. These associations were most clear in men and different between the pre-crisis and crisis period (p interaction = 0.023 and 0.035, respectively). CONCLUSIONS: The results suggest that economic crises strengthen the potential impact of job loss on harmful drinking, predominately among men.

Impact of Cross-Sectoral Alcohol Policy on Youth Alcohol Consumption.

OBJECTIVE: Cross-sectoral alcohol policy is recommended to reduce youth alcohol consumption, but little evidence is available on its effectiveness. Therefore, we examined whether regions and municipalities in the Dutch province of Noord-Brabant with stronger cross-sectoral alcohol policy showed larger reductions in alcohol consumption among adolescents aged 12-15. METHOD: Strong regional cross-sectoral alcohol policy was defined as participation in a regional alcohol prevention program. Strong municipal cross-sectoral alcohol policy was operationalized by measures on (a) sector variety: involvement of different policy sectors, and (b) strategy variety: formulation of different policy strategies. Relevant data from policy documents were searched for on the Internet. Data on trends in alcohol consumption were extracted from the 2007 and 2011 cross-sectional Youth Health Monitor that includes a random subset of adolescents aged 12-15 (n = 15,380 in 2007 and n = 15,437 in 2011). We used multilevel regression models. RESULTS: Two of the three regions in which municipalities participated in a regional alcohol prevention program showed a larger reduction in weekly drinking than the region in which municipalities did not participate (-12.2% and -13.4% vs. -8.3%). Municipalities with strong compared to weak sector variety showed a larger increase in adolescents' age at consuming their first alcoholic drink (0.63 vs. 0.42 years). Municipalities with strong strategy variety showed a decrease (-3.8%) in heavy weekly drinking, whereas those with weak variety showed an increase (5.1%). Cross-sectoral alcohol policy did not affect trends in other alcohol outcomes. CONCLUSIONS: Our results suggest that strong cross-sectoral alcohol policy may contribute to reducing some aspects of youth alcohol consumption. Monitoring policy implementation is needed to assess the full impact.

Changes between pre-crisis and crisis period in socioeconomic inequalities in health and stimulant use in Netherlands.

BACKGROUND: International research suggests an impact of economic crises on population health, with different effects among different socioeconomic groups. Since the end of 2008 the Netherlands experienced a period of economic crisis. Our study explores how inequalities in perceived general and mental health, and alcohol and tobacco use changed after the recession started. METHODS: We used data from the Dutch Health Interview Surveys: 2006-2008 (pre-crisis period) and 2009-2013 (crisis period). Respondents aged 25-64 were divided into socioeconomic groups based on labour status, income level and income change. Inequalities in health and stimulant use among these socioeconomic groups were described by period and changes between the pre-crisis and crisis period were investigated using logistic regression models. RESULTS: Most inequalities did not change, with some exceptions. For perceived general health, inequalities between employed persons and persons not in the labour force were larger in the crisis period (unfavourable trends for those not in the labour force). For smoking, inequalities between unemployed and employed persons were larger in the crisis period (decreasing smoking rates only for those employed), as did inequalities between persons with low and high income levels (decreasing smoking rates for those with higher income levels). Excessive drinking decreased among employed persons and persons with a decrease in income, while it remained stable among persons not in the labour force and among persons with an increase in income. CONCLUSION: The widening of some socioeconomic inequalities in health and stimulant use might suggest an enhanced vulnerability of lower socioeconomic groups to the post-2008 crisis.

Impact of the post-2008 economic crisis on harmful drinking in the Dutch working-age population.

BACKGROUND: Studies on the impact of economic crises on alcohol consumption have yielded ambiguous results. Therefore, we studied changes in trends in harmful drinking among Dutch working-age men and women after the post-2008 economic crisis started. We also assessed whether these trend changes differed across age and socioeconomic groups. METHODS: We used repeated cross-sectional data from the Dutch Health Interview Survey conducted by Statistics Netherlands. Representative samples were independently drawn each month (January, 2004-December, 2013). Our working-age study population consisted of 20,140 men and 22,394 women aged 25-64. For men and women, episodic drinking was defined as drinking ≥6 glasses on one day at least once a week. Chronic drinking was defined as consuming ≥14 glasses/week for women and ≥21 for men. Segmented logistic regression was used to model trend changes separately in men and women. RESULTS: A downward trend in episodic and chronic drinking before the crisis slowed down after the crisis started. For episodic drinking, we observed a ceasing-of-decline among men aged 35-44/45-54/55-64, compared to a start-of-decline among those aged 25-34 (p-interaction=0.042/0.020/0.047). For chronic drinking, we observed a ceasing-of-decline among women (p=0.023) but not among men in general (p=0.238). Among men, a ceasing-of-decline did occur in those with a high income, but a start-of-decline was found among those with a low income (p-interaction=0.049). CONCLUSION: In some subgroups of the Dutch working-age population, the downward trend in episodic and chronic drinking ceased after the crisis started. This suggests that the crisis had an upward effect on harmful drinking, but only in specific populations.

Translational research in nephrology: chronic kidney disease prevention and public health.

This narrative review evaluates translational research with respect to five important risk factors for chronic kidney disease (CKD): physical inactivity, high salt intake, smoking, diabetes and hypertension. We discuss the translational research around prevention of CKD and its complications both at the level of the general population, and at the level of those at high risk, i.e. people at increased risk for CKD or CKD complications. At the population level, all three lifestyle risk factors (physical inactivity, high salt intake and smoking) have been translated into implemented measures and clear population health improvements have been observed. At the 'high-risk' level, the lifestyle studies reviewed have tended to focus on the individual impact of specific interventions, and their wider implementation and impact on CKD practice are more difficult to establish. The treatment of both diabetes and hypertension appears to have improved, however the impact on CKD and CKD complications was not always clear. Future studies need to investigate the most effective translational interventions in low and middle income countries.

Illness Perceptions in Patients on Predialysis Care: Associations With Time Until Start of Dialysis and Decline of Kidney Function.

OBJECTIVES: Illness perceptions in patients with end-stage renal disease are associated with nonadherence and increased mortality. However, no data are available regarding the relationship between illness perceptions and accelerated disease progression in predialysis patients. METHODS: A total of 416 incident predialysis patients participating in a prospective cohort (PREPARE-2, Predialysis Patient Record-2) completed the Revised Illness Perception Questionnaire at the start of specialized predialysis care. The association between illness perceptions and time until start of dialysis was investigated using Cox regression models. Linear mixed modeling was used to test associations between illness perceptions and change of kidney function during predialysis care. Adjustments were made for sociodemographic, clinical, and biochemical factors. RESULTS: Five illness perceptions were associated with disease progression. Dialysis started earlier and kidney function declined faster (ml/min per 1.73 m/y) in patients who perceived their kidney disease as being cyclical in nature (adjusted hazard ratio [HRadj] = 1.32 [95% confidence interval {CI} = 1.11-1.56]; adjusted additional change = -0.64 [95% CI = -1.16 to -0.13]), having many negative consequences (HRadj = 1.47 [95% CI = 1.18-1.85]; adjusted additional change = -0.67 [-1.30 to -0.04]) and causing negative feelings (HRadj = 1.21 [95% CI = 1.03-1.42]; adjusted additional change = -0.65 [95% CI = -1.13 to -0.16]). In addition, kidney function declined faster in patients who perceived that their kidney disease cannot be personally controlled (adjusted additional change = -0.69 [95% CI = -1.31 to -0.09]) and who perceived that they did not fully understand their kidney disease (adjusted additional change = -0.53 [-1.05 to -0.01]). CONCLUSIONS: Stronger negative perceptions of illness at the start of predialysis care are a marker for accelerated disease progression. Detecting illness perceptions in predialysis patients may provide opportunities to intervene and slow down disease progression.

Lipid levels and renal function decline in pre-dialysis patients.

BACKGROUND: Little is known about the effect of low-density lipoprotein (LDL) cholesterol, triglyceride (TG), and high-density lipoprotein (HDL) cholesterol levels on renal function decline in patients receiving specialized pre-dialysis care. METHODS: In the prospective PREPARE-2 study, incident patients starting pre-dialysis care were included when referred to one of the 25 participating Dutch specialized pre-dialysis outpatient clinics (2004-2011). Clinical and laboratory data were collected every 6 months. A linear mixed model was used to compare renal function decline between patients with LDL cholesterol, TG, or HDL cholesterol levels above and below the target goals (LDL cholesterol: <2.50 mmol/l, TG: <2.25 mmol/l, and HDL cholesterol: ≥1.00 mmol/l). Additionally the HDL/LDL cholesterol ratio was investigated (≥0.4). RESULTS: In our study population (n = 306), the median age was 69 years and 70% were male. Patients with LDL cholesterol levels above the target of 2.50 mmol/l experienced an accelerated renal function decline compared to patients with levels below the target (crude additional decline: 0.10 ml/min/1.73 m(2)/month, 95% CI 0.00-0.20; p < 0.05). A similar trend was found for TG levels above the target of 2.25 mmol/l (0.05 ml/min/1.73 m(2)/month, 95% CI -0.06 to 0.16) and for a HDL/LDL cholesterol ratio below 0.4 (0.06 ml/min/1.73 m(2)/month, 95% CI -0.05 to 0.18). Adjustment for potential confounders resulted in similar results, and the exclusion of patients who were prescribed lipid-lowering medication (statin, fibrate, or cholesterol absorption inhibitor) resulted in a slightly larger estimated effect. CONCLUSION: High levels of LDL cholesterol were associated with an accelerated renal function decline, independent of the prescription of lipid-lowering medication.

How economic crises affect alcohol consumption and alcohol-related health problems: a realist systematic review.

Economic crises are complex events that affect behavioral patterns (including alcohol consumption) via opposing mechanisms. With this realist systematic review, we aimed to investigate evidence from studies of previous or ongoing crises on which mechanisms (How?) play a role among which individuals (Whom?). Such evidence would help understand and predict the potential impact of economic crises on alcohol consumption. Medical, psychological, social, and economic databases were used to search for peer-reviewed qualitative or quantitative empirical evidence (published January 1, 1990-May 1, 2014) linking economic crises or stressors with alcohol consumption and alcohol-related health problems. We included 35 papers, based on defined selection criteria. From these papers, we extracted evidence on mechanism(s), determinant, outcome, country-level context, and individual context. We found 16 studies that reported evidence completely covering two behavioral mechanisms by which economic crises can influence alcohol consumption and alcohol-related health problems. The first mechanism suggests that psychological distress triggered by unemployment and income reductions can increase drinking problems. The second mechanism suggests that due to tighter budget constraints, less money is spent on alcoholic beverages. Across many countries, the psychological distress mechanism was observed mainly in men. The tighter budget constraints mechanism seems to play a role in all population subgroups across all countries. For the other three mechanisms (i.e., deterioration in the social situation, fear of losing one's job, and increased non-working time), empirical evidence was scarce or absent, or had small to moderate coverage. This was also the case for important influential contextual factors described in our initial theoretical framework. This realist systematic review suggests that among men (but not among women), the net impact of economic crises will be an increase in harmful drinking. Such a different net impact between men and women could potentially contribute to growing gender-related health inequalities during a crisis.

The impact of extended closing times of alcohol outlets on alcohol-related injuries in the nightlife areas of Amsterdam: a controlled before-and-after evaluation.

BACKGROUND AND AIMS: The municipality of Amsterdam implemented a new alcohol policy allowing alcohol outlets in two of the five nightlife areas to extend their closing times from 1 April 2009 onwards. We investigated how levels and trends of alcohol-related injuries changed after implementation of this alcohol policy, by comparing areas with extended closing times to those without. DESIGN: A controlled before-and-after evaluation to compare changes in alcohol-related injuries between intervention and control areas. SETTING: Central district of Amsterdam, The Netherlands. PARTICIPANTS: Alcohol-related ambulance attendances for control and intervention areas between 1 April 2006 and 1 April 2009 (respectively, n = 544 and n = 499) and between 1 April 2009 and 1 April 2011 (respectively, n = 357 and n = 480). MEASUREMENTS: Alcohol-related injuries were defined as ambulance attendances for people who suffered from direct or indirect consequences of alcohol consumption. Injuries were counted per month in two intervention and three control nightlife areas. We used Poisson regression to assess changes in injuries. FINDINGS: After 1 April 2009, intervention areas showed a larger change in the level of alcohol-related injuries than control areas [incidence rate ratio 1.34, 95% confidence interval (CI) = 1.12, 1.61], but trends remained stable in all areas. This increase was only statistically significant for the following subgroups: 2.00-5.59 a.m., weekend days, men, individuals aged 25-34 years, and people transported to a hospital. However, the increase did not differ between subgroups with statistical significance. CONCLUSIONS: A 1-hour extension of alcohol outlet closing times in some of Amsterdam's nightlife areas was associated with 34% more alcohol-related injuries.

Uric acid: association with rate of renal function decline and time until start of dialysis in incident pre-dialysis patients.

BACKGROUND: In patients with chronic kidney disease (CKD) hyperuricemia is common. Evidence that hyperuricemia might also play a causal role in vascular disease, hypertension and progression of CKD is accumulating. Therefore, we studied the association between baseline uric acid (UA) levels and the rate of decline in renal function and time until start of dialysis in pre-dialysis patients. METHODS: Data from the PREPARE-2 study were used. The PREPARE-2 study is an observational prospective cohort study including incident pre-dialysis patients with CKD stages IV-V in the years between 2004 and 2011. Patients were followed for a median of 14.9 months until start of dialysis, kidney transplantation, death, or censoring. Main outcomes were the change in the rate of decline in renal function (measured as estimated glomerular filtration rate (eGFR)) estimated using linear mixed models, and time until start of dialysis estimated using Cox proportional hazards models. RESULTS: In this analysis 131 patients were included with a baseline UA level (mean (standard deviation (SD)) of 8.0 (1.79) mg/dl) and a mean decline in renal function of -1.61 (95% confidence interval (CI), -2.01; -1.22) ml/min/1.73 m2/year. The change in decline in GFR associated with a unit increase in UA at baseline was -0.14 (95% CI -0.61;0.33, p=0.55) ml/min/1.73 m2/year. Adjusted for demography, comorbidities, diet, body mass index (BMI), blood pressure, lipids, proteinuria, diuretic and/or allopurinol usage the change in decline in eGFR did not change. The hazard ratio (HR) for starting dialysis for each mg/dl increase in UA at baseline was 1.08 (95% CI, 0.94;1.24, p=0.27). After adjustment for the same confounders the HR became significant at 1.26 (95% CI, 1.06;1.49, p=0.01), indicating an earlier start of dialysis with higher levels of UA. CONCLUSION: Although high UA levels are not associated with an accelerated decline in renal function, a high serum UA level in incident pre-dialysis patient is a risk factor for an earlier start of dialysis.

Course of symptoms and health-related quality of life during specialized pre-dialysis care.

BACKGROUND: Concerns are present on the limited value of renal function alone in defining the optimal moment to start dialysis. Disease-related symptoms and health-related quality of life (HRQOL) may have additional clinical value in defining this moment, but little is known about how these parameters change during pre-dialysis care. The aims of our study were to describe the course of symptoms and HRQOL during pre-dialysis care and to investigate their association with poor health outcomes. METHODS: In the prospective PREPARE-2 cohort, incident patients starting specialized pre-dialysis care were included when referred to one of the 25 participating Dutch outpatient clinics (2004-2011). In the present analysis, 436 patients with data available on symptoms and HRQOL were included. Clinical data, symptoms (revised illness perception questionnaire), and HRQOL (short form-36 questionnaire; physical and mental summary score) were collected every 6-month interval. A time-dependent Cox proportional hazard model was used to associate symptoms and HRQOL with the combined poor health outcome (i.e. starting dialysis, receiving a kidney transplant, and death). RESULTS: All symptoms increased, especially fatigue and loss of strength, and both the physical and mental summary score decreased over time, with the most pronounced change during the last 6-12 months of follow-up. Furthermore, each additional symptom (adjusted HR 1.04 (95% CI, 1.00-1.09)) and each 3-point lower physical and mental summary score (adjusted HR 1.04 (1.02-1.06) and 1.04 (1.02-1.06) respectively) were associated with a higher risk of reaching the combined poor health outcome within the subsequent 6 months. CONCLUSIONS: The number of symptoms increased and both the physical and mental HRQOL score decreased during pre-dialysis care and these changes were associated with starting dialysis, receiving a kidney transplant, and death. These results may indicate that symptoms and HRQOL are good markers for the medical condition and disease stage of pre-dialysis patients.

Haemoglobin levels and health-related quality of life in young and elderly patients on specialized predialysis care.

BACKGROUND: In predialysis patients, the optimal treatment choices for controlling haemoglobin (Hb) are unknown, because targeting high Hb levels has negative effects--poorer survival--but possible positive effects as well--better health-related quality of life (HRQOL). Moreover, these effects may be different in specific subgroups (e.g. young versus elderly). METHODS: In the PREPARE-2 follow-up study, incident predialysis patients were included (2004-2011) when referred to 1 of the 25 participating Dutch outpatient clinics. HRQOL was assessed at 6-month intervals with the short form-36 (SF-36) questionnaire [physical/mental summary measure and eight subscales (range 0-100)]. A linear mixed model was used to associate Hb [<11, ≥ 11 to <12 (reference), ≥ 12 to <13 and ≥ 13 g/dL] with HRQOL, stratified by prescription of anaemia medication (erythropoietin-stimulating agent (ESA)/iron) and age (young: <65 years and elderly: ≥ 65 years). RESULTS: Only elderly patients (n = 214) not prescribed ESA/iron and with a high Hb (≥ 13 versus ≥ 11 to <12 g/dL) had a statistically significant (P < 0.05) and/or clinically relevant (>3-5 points) higher physical [11.9, 95% confidence interval (CI) 1.7, 22.2] and mental (6.4, 95% CI -1.7, 14.6) summary score. High Hb was not associated with a higher HRQOL in elderly patients who were prescribed ESA/iron. However, only young patients (n = 157) prescribed ESA/iron and with a high Hb (≥ 13 versus ≥ 11 to <12 g/dL) had a higher physical (8.9, 95% CI 2.1, 15.8) and mental (6.2, 95% CI -0.4, 12.8) summary score. CONCLUSIONS: The association of Hb levels with HRQOL differs by age and use of ESA/iron medication on predialysis care. Therefore, medical care should aim for shared decision-making regarding the appropriate Hb target leading to more individualized care.

Renal function in familial longevity: the Leiden Longevity Study.

Studying renal function in subjects with a familial propensity for longevity may provide insight in (un)known mechanisms that determine the age-related decline in renal function of normal subjects. In the Leiden Longevity Study, middle-aged offspring of non-agenarian siblings and their partners as environmentally matched controls were included. Information was collected on lifestyle, medical history, medication use, and a non-fasting blood sample was drawn. Renal function (estimated glomerular filtration rate, eGFR) was assessed with the Chronic Kidney Disease epidemiology collaboration (CKD-EPI) formula. Linear mixed models were used to account for familial dependencies within the offspring and all analyses were stratified by sex. eGFR was similar between female offspring and female controls (0.44ml/min/1.73m(2) (SE 0.72) difference, p=0.54, age-adjusted). Male offspring had a higher eGFR compared to male controls (1.78ml/min/1.73m(2) (SE 0.78) difference, p=0.022, age-adjusted), and further adjustments for various characteristics did not materially change this difference. Among men with a history of hypertension, or myocardial infarction and/or stroke, offspring had a higher eGFR compared to controls (4.74ml/min/1.73m(2) (SE 1.53) difference, p=0.002, age-adjusted, and 6.21ml/min/1.73m(2) (SE 2.85) difference, p=0.033, age-adjusted, respectively). Middle-aged men, but not women, with a propensity for longevity have better renal function compared to environmentally matched controls, especially among those with a history of cardiovascular disease.

Audit-based education: a potentially effective program for improving guideline achievement in CKD patients.

The achievement of treatment guidelines in patients with chronic kidney disease is poor, and more efforts are needed to improve this. Audit-based education is a program that may contribute to this improvement. de Lusignana et al. investigated whether audit-based education is effective in lowering systolic blood pressure in a primary-care setting. Although the program is inventive and promising, several adjustments are needed before it can be applied as an effective strategy.

Differences in progression to ESRD between black and white patients receiving predialysis care in a universal health care system.

BACKGROUND AND OBJECTIVES: Studies performed in the United States showed that blacks progress from CKD to ESRD faster than do whites. Possible explanations are differences in health care system factors. This study investigated whether progression is also faster in a universal health care system, where all patients receive comparable care. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Data from the PREdialysis PAtient REcord study, a multicenter follow-up study of patients with CKD who started predialysis care in The Netherlands (1999-2011), were analyzed. Time-dependent Cox proportional hazards models were used to estimate the hazard ratio (HR) for starting renal replacement therapy (RRT), and linear mixed models were used to compare renal function decline (RFD) between blacks and whites. To explore possible mechanisms, analyses were adjusted for patient characteristics. RESULTS: At initiation of predialysis care, blacks (n=49) were younger and had more diabetes mellitus, higher proteinuria levels, and a higher estimated GFR than whites (n=946). Median follow-up time in months was similar (blacks: 13.9 [boundaries of interquartile range (IQR), 5.3 to 19.5]; whites: 13.1 [IQR, 5.1 to 24.0]). For blacks compared with whites, the crude HR for starting RRT within the first 15 months was 0.86 (95% confidence interval [CI], 0.55 to 1.34) and from 15 months onward, 1.93 (95% CI, 1.02 to 3.68), which increased after adjustment. RFD was faster by 0.18 (95% CI, 0.05 to 0.32) ml/min per 1.73 m(2) per month in blacks compared with whites. CONCLUSION: Blacks receiving predialysis care in a universal health care system have faster disease progression than whites, suggesting that health care system factors have a less influential role than had been thought in explaining black-white differences.

Multiple imputation: dealing with missing data.

In many fields, including the field of nephrology, missing data are unfortunately an unavoidable problem in clinical/epidemiological research. The most common methods for dealing with missing data are complete case analysis-excluding patients with missing data--mean substitution--replacing missing values of a variable with the average of known values for that variable-and last observation carried forward. However, these methods have severe drawbacks potentially resulting in biased estimates and/or standard errors. In recent years, a new method has arisen for dealing with missing data called multiple imputation. This method predicts missing values based on other data present in the same patient. This procedure is repeated several times, resulting in multiple imputed data sets. Thereafter, estimates and standard errors are calculated in each imputation set and pooled into one overall estimate and standard error. The main advantage of this method is that missing data uncertainty is taken into account. Another advantage is that the method of multiple imputation gives unbiased results when data are missing at random, which is the most common type of missing data in clinical practice, whereas conventional methods do not. However, the method of multiple imputation has scarcely been used in medical literature. We, therefore, encourage authors to do so in the future when possible.