Using Relative Survival to Estimate the Burden of Kidney Failure.

RATIONALE & OBJECTIVE: Estimates of mortality from kidney failure are misleading because the mortality from kidney failure is inseparable from the mortality attributed to comorbid conditions. We sought to develop an alternative method to reduce the bias in estimating mortality due to kidney failure using life table methods. STUDY DESIGN: Longitudinal cohort study. SETTING & PARTICIPANTS: Using data from the US Renal Data System and the Medicare 5% sample, we identified an incident cohort of patients, age 66+, who first had kidney failure in 2009 and a similar general population cohort without kidney failure. EXPOSURE: Kidney failure. OUTCOME: Death. ANALYTICAL APPROACH: We created comorbidity, age, sex, race, and year-specific life tables to estimate relative survival of patients with incident kidney failure and to attain an estimate of excess kidney failure-related deaths. Estimates were compared with those based on standard life tables (not adjusted for comorbidity). RESULTS: The analysis included 31,944 adults with kidney failure with a mean age of 77±7 years. The 5-year relative survival was 31% using standard life tables (adjusted for age, sex, race, and year) versus 36% using life tables also adjusted for comorbidities. Compared with other chronic diseases, patients with kidney failure have among the lowest relative survival. Patients with incident kidney failure ages 66-70 and 76-80 have a survival comparable to adults without kidney failure roughly 86-90 and 91-95 years old, respectively. LIMITATIONS: Relative survival estimates can be improved by narrowing the specificity of the covariates collected (eg, disease severity and ethnicity). CONCLUSIONS: Estimates of survival relative to a matched general population partition the mortality due to kidney failure from other causes of death. Results highlight the immense burden of kidney failure on mortality and the importance of disease prevention efforts among older adults. PLAIN-LANGUAGE SUMMARY: Estimates of death due to kidney failure can be misleading because death information from kidney failure is intertwined with death due to aging and other chronic diseases. Life tables are an old method, commonly used by actuaries and demographers to describe the life expectancy of a population. We developed life tables specific to a patient's age, sex, year, race, and comorbidity. Survival is derived from the life tables as the percentage of patients who are still alive in a specified period. By comparing survival of patients with kidney failure to the survival of people from the general population, we estimate that patients with kidney failure have one-third the chance of survival in 5 years compared with people with similar demographics and comorbidity but without kidney failure. The importance of this measure is that it provides a quantifiable estimate of the immense mortality burden of kidney failure.

Design of randomized clinical trials with a binary endpoint: Conditional versus unconditional analyses of a two-by-two table.

When designing a randomized clinical trial to compare two treatments, the sample size required to have desired power with a specified type 1 error depends on the hypothesis testing procedure. With a binary endpoint (e.g., response), the trial results can be displayed in a 2 × 2 table. If one does the analysis conditional on the number of positive responses, then using Fisher's exact test has an actual type 1 error less than or equal to the specified nominal type 1 error. Alternatively, one can use one of many unconditional "exact" tests that also preserve the type 1 error and are less conservative than Fisher's exact test. In particular, the unconditional test of Boschloo is always at least as powerful as Fisher's exact test, leading to smaller required sample sizes for clinical trials. However, many statisticians have argued over the years that the conditional analysis with Fisher's exact test is the only appropriate procedure. Since having smaller clinical trials is an extremely important consideration, we review the general arguments given for the conditional analysis of a 2 × 2 table in the context of a randomized clinical trial. We find the arguments not relevant in this context, or, if relevant, not completely convincing, suggesting the sample-size advantage of the unconditional tests should lead to their recommended use. We also briefly suggest that since designers of clinical trials practically always have target null and alternative response rates, there is the possibility of using this information to improve the power of the unconditional tests.

Does Examination Table Paper Use Mitigate the Risk of Disease Transmission in a Family Medicine Clinic?

Reducing examination table paper (ETP) use may help curb carbon emissions from health care. Six participants applied Glo Germ (DMA International) to their hands before a common physical examination (abdominal, cardiorespiratory, hip and knee) both with and without ETP. After each exam, UV light was shined on the exam table and photographs were taken. The number of hand touches on ETP-covered areas and uncovered areas were tallied and compared using t tests. Despite covering more surface area, participants touched areas without ETP significantly more than ETP-covered areas (P <.05). Despite its continued use, patients do not have much hand contact with ETP during common clinical examinations.

The lifetime risk of surgery in England: a nationwide observational cohort study.

BACKGROUND: The average number of times a person will have surgery in their lifetime, and the amount of surgical healthcare resources they use, is unknown. Lifetime risk is a measure of the risk of an average person having a specific event within their lifetime. We report the lifetime risk of surgery and the change observed during the first year of the COVID-19 pandemic. METHODS: We conducted a population cohort study using hospital episode statistics to identify all patients undergoing surgery between January 1, 2016, and December 31, 2020, in England. We calculated age- and sex-specific incidence rates of surgery and combined these with routinely available population and mortality data from the Office for National Statistics. We computed the probability of requiring surgery stratified by 5-yr epochs (age 0-4 to ≥90 yr). Our primary analysis calculated lifetime risk for all surgery using the life table method. We assessed the impact of the COVID-19 pandemic, comparing a pre-pandemic and a pandemic period. RESULTS: Between 2016 and 2020, 23 427 531 patients underwent surgery, of which 11 937 062 were first surgeries. The average denominator population for England was 55.9 million. The lifetime risk of first surgery was 60.2% (95% confidence interval 55.1-65.4%) for women and 59.1% (95% confidence interval 54.2-64.1%) for men. The COVID-19 pandemic decreased the lifetime risk of first surgery by 32.3% for women and by 31.7% for men. This estimated lifetime risk should only be applied to the English population. CONCLUSIONS: This population epidemiological analysis suggests that approximately 60% of people in England will undergo surgery in their lifetime.

Age- and cause-specific contributions to increase in life expectancy at birth in Korea, 2000-2019: a descriptive study.

BACKGROUND: Korea's life expectancy at birth has consistently increased in the 21st century. This study compared the age and cause-specific contribution to the increase in life expectancy at birth in Korea before and after 2010. METHODS: The population and death numbers by year, sex, 5-year age group, and cause of death from 2000 to 2019 were acquired. Life expectancy at birth was calculated using an abridged life table by sex and year. The annual age-standardized and age-specific mortality by cause of death was also estimated. Lastly, the age and cause-specific contribution to the increase in life expectancy at birth in the two periods were compared using a stepwise replacement algorithm. RESULTS: Life expectancy at birth in Korea increased consistently from 2010 to 2019, though slightly slower than from 2000 to 2009. The cause-specific mortality and life expectancy decomposition analysis showed a significant decrease in mortality in chronic diseases, such as neoplasms and diseases of the circulatory system, in the middle and old-aged groups. External causes, such as transport injuries and suicide, mortality in younger age groups also increased life expectancy. However, mortality from diseases of the respiratory system increased in the very old age group during 2010-2019. CONCLUSIONS: Life expectancy at birth in Korea continued to increase mainly due to decreased mortality from chronic diseases and external causes during the study period. However, the aging of the population structure increased vulnerability to respiratory diseases. The factors behind the higher death rate from respiratory disease should be studied in the future.

Portosystemic Hepatic Encephalopathy Scores (PHES) differ between Danish and German healthy populations despite their geographical and cultural similarities.

Minimal hepatic encephalopathy (MHE) is common in liver cirrhosis and is identified by psychometric tests. The portosystemic hepatic encephalopathy score (PHES) is the most widely used and serves as an inter-study comparator. PHES has not been standardised for use in the Danish population, where German normal values have been applied until now based on the notion that the populations are comparable. This study aimed to evaluate if German PHES normal values can be applied in the Danish population and establish Danish normal values if needed. 200 Danish and 217 German healthy persons underwent Number Connection Test A and B (NCT), Line Tracing Test (LTT), Digit Symbol Test (DST), and Serial Dotting Test (SDT), and based on performance, PHES was calculated. German and Danish PHES performance declined with age in all subtests but more rapidly in Danes. Both German and Danish norms were impacted by gender and education, but to a different extent in the single tests of the test battery. Accordingly, there was a need for specific Danish normal values, which are presented here. Applying the new Danish normal values instead of the German in patients with cirrhosis yielded a lower percentage of out-of-norm performances (58% vs. 66%) and, hence, a lower prevalence of MHE. Danes and Germans perform differently on PHES, and therefore, normal German values cannot be used in Danish patients. Danish normal values are presented here and yield a lower number of 'out of norm' performances.

Time and temperature abuse of milk in conditions representing a school cafeteria share table does not meaningfully reduce microbial quality.

Share tables (ST) are tables or stations in school cafeterias where students can return unopened foods and beverages, providing an opportunity to access these items at no cost. Currently, research suggests that milk is among the most wasted items in breakfast and lunch programs in the United States. Share tables present a simple solution for reducing milk waste, but research is needed to understand the microbial spoilage potential of milk in ST. To this end, uninoculated milk cartons and milk cartons inoculated with 2 to 3 log10(cfu/mL) Pseudomonas poae, a fast-growing psychrotroph, was exposed to ambient temperature during winter (mean temperature = 20.3°C) and summer (23.1°C) for 125 min, repeated over 5 d (the length of a school week). Microbial counts in the inoculated milk cartons increased linearly, exceeding the spoilage threshold of 6.0 log10(cfu/mL) after d 3 and after d 4 in the winter and summer season trials, respectively. In the winter trial, the microbial counts for uninoculated milk cartons never exceeded the lower limit of detection, 2.31 log10(cfu/mL), and in the summer trials, microbial counts never reached the spoilage threshold, indicating that initial contamination is a driving factor of microbial milk spoilage. Regardless of sharing status or seasonality, the greatest changes in counts for inoculated milk cartons occurred during overnight refrigeration, ranging from 0.56 to 1.4 log10(cfu/mL), while during the share table ranged from no observable change up to 0.29 log10(cfu/mL), emphasizing that school nutrition personnel should focus efforts on tightly controlling refrigeration temperatures and returning milk to refrigeration as soon as possible. A previously developed model for school cafeteria share tables was adapted to understand the typical residence time of milk in a simulated cafeteria with an ambient temperature share table for the summer and winter seasons over 1,000 wk. Milk was predicted to have a very short mean residence time (85 min) regardless of sharing status or season, with 99.8% of milk consumed, discarded, or donated within the first 2 d. As a result, only 3 out of 451,410 and 6 out of 451,410 simulated milks spoiled in the winter and summer seasons, respectively. The data generated here can be used to inform science-based decision-making for including milk in share tables, or applied to any system where one might have to accept short-term unrefrigerated storage of milk to meet a waste reduction or food security goal.

Improving the effectiveness of CPR during interventional procedures.

INTRODUCTION: The number of interventional procedures, such as transcatheter aortic valve replacements or thoracic endovascular aortic repairs, is on the rise. Intraprocedural cardiac arrest is a rare occurrence during high-risk procedures. Modern hybrid-operating tables may adversely affect chest compression quality due to their flexibility. To investigate this relationship, we analyzed the blood pressure generated during chest compressions at different degrees of table extension and assessed the effect of an additional stabilization bar to secure the table. METHODS: A CPR manikin was connected to online blood pressure monitoring on a hybrid operating table. Chest compressions were administered using a mechanical device (at 100 bpm and 80 bpm). Hemodynamic effects were evaluated at various degrees of table extension (0%, 50%, 100% table extension) and with the addition of a stabilization bar. RESULTS: A greater degree of table extension was associated with lower diastolic blood pressure. The addition of a stabilization bar alleviated this drop in diastolic blood pressure and enabled the generation of higher mean arterial pressures at 50% and 100% table extension during chest compressions. CONCLUSION: The flexibility of a hybrid operating table adversely impacts the hemodynamic effect of chest compressions. This effect may be mitigated by using a stabilization bar. These results may be relevant for providing further recommendations for CPR guidelines in hybrid OR settings.

Sublethal effects of a spiromesifen and abamectin combination on Tetranychus urticae (Acari: Tetranychidae) and its predators Phytoseiulus persimilis and Amblyseius swirskii (Acari: Phytoseiiidae).

The two-spotted spider mite, Tetranychus urticae Koch (TSSM), is an important cosmopolitan pest of agricultural crops that is often managed in greenhouses by augmentation of predatory mites in combination with acaricides. Here we examined the transgenerational effects of low lethal concentrations of a widely-used acaricide, Oberon Speed® (a combination of spiromesifen and abamectin), on the life history traits and population growth of T. urticae and two of its predators, Phytoseiulus persimilis Athias-Henriot and Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae). The concentrations employed corresponded to the LC10, LC20 and LC30 values estimated for TSSM protonymphs 48 h post-exposure in a topical bioassay, which yielded an LC50 value of 207.2 ppm. Parental exposure of TSSM to all three low concentrations increased the total developmental time of progeny; both the LC20 and LC30 treatments reduced adult longevity and number of oviposition days, but only the LC30 treatment increased the preoviposition period. Similarly, both the LC20 and LC30 treatments significantly reduced life table parameters (r, R0, λ, and GRR), and increased generation time (T) and population doubling time (DT). Although maternal exposure to the acaricide had various impacts on progeny life history, A. swirskii was less affected than P. persimilis, suggesting the former species would be more compatible for integration with Oberon Speed® for control of T. urticae in greenhouse vegetable production.

Comparative Analysis of Deterministic and Nondeterministic Decision Trees for Decision Tables from Closed Classes.

In this paper, we consider classes of decision tables with many-valued decisions closed under operations of the removal of columns, the changing of decisions, the permutation of columns, and the duplication of columns. We study relationships among three parameters of these tables: the complexity of a decision table (if we consider the depth of the decision trees, then the complexity of a decision table is the number of columns in it), the minimum complexity of a deterministic decision tree, and the minimum complexity of a nondeterministic decision tree. We consider the rough classification of functions characterizing relationships and enumerate all possible seven types of relationships.

Likelihood Ratio Test and the Evidential Approach for 2 × 2 Tables.

Categorical data analysis of 2 × 2 contingency tables is extremely common, not least because they provide risk difference, risk ratio, odds ratio, and log odds statistics in medical research. A χ2 test analysis is most often used, although some researchers use likelihood ratio test (LRT) analysis. Does it matter which test is used? A review of the literature, examination of the theoretical foundations, and analyses of simulations and empirical data are used by this paper to argue that only the LRT should be used when we are interested in testing whether the binomial proportions are equal. This so-called test of independence is by far the most popular, meaning the χ2 test is widely misused. By contrast, the χ2 test should be reserved for where the data appear to match too closely a particular hypothesis (e.g., the null hypothesis), where the variance is of interest, and is less than expected. Low variance can be of interest in various scenarios, particularly in investigations of data integrity. Finally, it is argued that the evidential approach provides a consistent and coherent method that avoids the difficulties posed by significance testing. The approach facilitates the calculation of appropriate log likelihood ratios to suit our research aims, whether this is to test the proportions or to test the variance. The conclusions from this paper apply to larger contingency tables, including multi-way tables.

Searching for precision: Lorenz Eichstadt's Tabulae harmonicae coelestium motuum (Stetin 1644) and astronomical prediction after Kepler.

In the century between the creation of the first large, European astronomical observatory by Tycho Brahe in the 1580s and the national observatories of France and England in the 1660-1670s, astronomers constructed ever more sets of tables, derived from various geometrical and physical models, to compute planetary positions. But how were these tables to be evaluated? What level of precision or accuracy should be expected from mathematical astronomy? In 1644, the Stetin astronomer and calendar-maker Lorenz Eichstadt published a new set of tables, mostly cobbled together from earlier tables, which include a running commentary on how his tables might be expected to match 'observed' planetary positions. His earlier works also often display a rhetoric of 'exactitude' and 'error'. Eichstadt thus offers a case study of explicit discussions of 'precision' in mid-seventeenth astronomy. Although some tables could generate positions to arcseconds, Eichstadt argued that a regime of five arcminutes should be enough for most table users who were, presumably, computing horoscopes.

Efficacy and safety of monoclonal antibodies targeting CGRP in migraine prevention. GRADE tables elaborated by the ad hoc working group of the International Headache Society.

OBJECTIVES: Grading of Recommendations, Assessment Development and Evaluation (GRADE) tables were created using a standardized and independent assessment of the efficacy and side effects of treatments with monoclonal antibodies (mAb) against calcitonin gene-related peptide (CGRP) or the CGRP receptor for the prevention of migraine. We hope to provide support for author groups writing national or regional treatment or management guidelines for migraine prevention. METHODS: We formulated patient/population, intervention, comparison and outcomes (PICO) questions for the efficacy and safety of mAb against CGRP or the CGRP-receptor for the prevention of migraine attacks. We performed a systematic literature research for randomized studies with eptinezumab, erenumab, fremanezumab and galcanezumab and a pooled analysis was done, using RevMan 5.4 software. For dichotomous outcomes we used risk ratio, and for continuous outcomes we used the mean difference to compare and summarize the evidence between groups. The evidence across studies, for each outcome, except serious adverse events, was assessed using GRADE evidence tables. Additionally, we report the serious adverse effects in the tables of the characteristics of the studies. RESULTS: All mAb are superior to placebo for the reduction in monthly migraine days (days in which a headache consistent with migraine occurred) in participants with episodic and chronic migraine. There are no major differences between the mAb. CONCLUSIONS: The GRADE evidence summary tables provided will support author groups to write treatment guidelines for the prevention of migraine with mAb.

Exact inference for fixed effects meta-analysis of 2 × 2 $$ 2\times 2 $$ tables.

Meta-analysis of associations between rare outcomes and binary exposures are particularly important in studies of a drug's potential side-effects. But meta-analysis of the resulting 2 × 2 $$ 2\times 2 $$ contingency tables presents substantial practical difficulties, as analysts are currently forced to pick between "exact" inference-that eliminates concern over using large-sample approximations with small cell counts-and explicitly allowing for heterogeneity of the underlying effects. A controversial example is given by the Avandia meta-analysis (Nissen and Wolski. N Engl J Med. 2007;356(24):2457-2471) of rosiglitazone's effects on myocardial infarction and death. While the initial Avandia analysis-using simple methods-found a significant effect, its results conflict with subsequent re-analyses that use either exact methods, or that explicitly acknowledge the plausible heterogeneity. In this article, we aim to resolve these difficulties, by providing an exact (albeit conservative) method that is valid under heterogeneity. We also provide a measure of the degree of conservatism, that indicates the approximate extent of the excess coverage. Applied to the Avandia data, we find support for Nissen and Wolski 2007's original results. Given that our method does not require strong assumptions or large cell counts, and provides intervals around the well-known conditional maximum likelihood estimate, we anticipate that it could be an attractive default method for meta-analysis of 2 × 2 $$ 2\times 2 $$ tables featuring rare events.

A new cure model that corrects for increased risk of non-cancer death: analysis of reliability and robustness, and application to real-life data.

BACKGROUND: Non-cancer mortality in cancer patients may be higher than overall mortality in the general population due to a combination of factors, such as long-term adverse effects of treatments, and genetic, environmental or lifestyle-related factors. If so, conventional indicators may underestimate net survival and cure fraction. Our aim was to propose and evaluate a mixture cure survival model that takes into account the increased risk of non-cancer death for cancer patients. METHODS: We assessed the performance of a corrected mixture cure survival model derived from a conventional mixture cure model to estimate the cure fraction, the survival of uncured patients, and the increased risk of non-cancer death in two settings of net survival estimation, grouped life-table data and individual patients' data. We measured the model's performance in terms of bias, standard deviation of the estimates and coverage rate, using an extensive simulation study. This study included reliability assessments through violation of some of the model's assumptions. We also applied the models to colon cancer data from the FRANCIM network. RESULTS: When the assumptions were satisfied, the corrected cure model provided unbiased estimates of parameters expressing the increased risk of non-cancer death, the cure fraction, and net survival in uncured patients. No major difference was found when the model was applied to individual or grouped data. The absolute bias was < 1% for all parameters, while coverage ranged from 89 to 97%. When some of the assumptions were violated, parameter estimates appeared more robust when obtained from grouped than from individual data. As expected, the uncorrected cure model performed poorly and underestimated net survival and cure fractions in the simulation study. When applied to colon cancer real-life data, cure fractions estimated using the proposed model were higher than those in the conventional model, e.g. 5% higher in males at age 60 (57% vs. 52%). CONCLUSIONS: The present analysis supports the use of the corrected mixture cure model, with the inclusion of increased risk of non-cancer death for cancer patients to provide better estimates of indicators based on cancer survival. These are important to public health decision-making; they improve patients' awareness and facilitate their return to normal life.

Life expectancy and healthy life expectancy of Korean registered disabled by disability type in 2014-2018: Korea National Rehabilitation Center database.

BACKGROUND: Conducting a distinct comparison between the life expectancy (LE) and healthy life expectancy (HALE) of people with disabilities (PWDs) and the general population is necessary due to the various environmental and health conditions they encounter. Therefore, this study aimed to develop the life table for PWDs and calculate those of LE and HALE based on sex, severity, and disability types among the registered Korean PWDs. METHODS: We used aggregated data of registered PWDs from the Korea National Rehabilitation Center database between 2014 and 2018. Overall, 345,595 deaths were included among 12,627,428 registered PWDs. First, we calculated the LE for total PWDs and non-disabled people using a standard life table, extending the old age mortality among nine models. Subsequently, we calculated the LE for each type of disability using the relationship between the mortality of total PWDs and those of each type of disability. Finally, HALE was calculated using the Sullivan method for three types as follows: disability-free and perceived health (PH) using the National Survey, and hospitalized for ≥ 7 days using the Korea National Health Insurance System (NHIS) database. RESULTS: The calculated LE/HALE-NHIS (years) at registration in males and females were 81.32/73.32 and 87.38/75.58, 68.54/58.98 and 71.43/59.24, 73.87/65.43 and 78.25/67.51, and 61.53/50.48 and 62.41/49.72 years among non-disabled, total PWDs, mild disabled, and severe disabled, respectively. LE/HALE-NHIS was lowest and highest in respiratory dysfunction and hearing disabilities, respectively. CONCLUSIONS: Males with disabilities had shorter LE and HALE at registration than females, except for those with severe disabilities, and there were variabilities in the LE based on the disability types.

Comparison of percentile tables and algorithm-based calculators for classification of blood pressures in children and adolescents with obesity: A secondary analysis of a clinical trial.

AIM: Obesity as a major risk factor for childhood hypertension necessitates careful blood pressure (BP) monitoring of those affected. This study aimed to compare BP classification in a cohort of children affected by obesity using tables versus digital calculations in two sets of guidelines. METHODS: This study was a secondary analysis of data collected from a randomised clinical trial of a multidisciplinary life-style assessment and intervention program. Baseline data from 237 children with a body mass index >99th percentile or >91st percentile with weight-related comorbidities and available BP measurements were analysed. We assessed agreement between tables and algorithms in classification of elevated BP/pre-hypertension and hypertension based on the American Academy of Paediatrics (AAP) clinical practice guidelines (CPG) and the older Fourth Report using Cohen's weighted kappa. The prevalence of hypertensive diagnoses was also compared between the two guidelines. RESULTS: Agreement between BP tables and algorithmic calculation of percentiles was discordant, though improved in the AAP CPG compared to the Fourth Report (Cohen's kappa = 0.70 vs. 0.57, respectively). None (0%) were missed diagnoses, and 59 (24.9%) were false positives for the Fourth Report, and 0 (0%) were missed diagnoses, and 49 (20.9%) were false positives for the AAP CPG. Under the recent guidelines, there was an increase in prevalence of 6.0% (95% confidence interval (CI) 2.5-9.4%; P = 0.0001) for BP ≥90th percentile, and of 3.0% (95% CI 0.4-5.6%; p = 0.016) for hypertension (BP ≥ 95th percentile) in the cohort (18.0% and 6.8%, respectively, increased from 12.0% and 3.8%). CONCLUSIONS: Digital calculators over tables in clinical practice are recommended where possible to improve the accuracy of paediatric BP classification. Substantial rates of elevated BP/Hypertension were found in this cohort of children and adolescents with overweight and obesity.

Do people change their eating habits after a diagnosis of cancer? A systematic review.

BACKGROUND: People who live with and beyond cancer are considered to be motivated to change their diet. However, there is a lack of reviews conducted on what specific dietary changes people make and further evaluation may inform future interventional studies. Hence, we aim to summarise the evidence on dietary changes in observational studies before and after a cancer diagnosis. METHODS: This systematic review followed the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Electronic searches were conducted in four databases to identify cohort and cross-sectional studies on dietary changes before and after a cancer diagnosis, excluding studies that evaluated an intervention. Quality assessment was undertaken, and meta-analyses were conducted where suitable. RESULTS: We identified 14 studies with 16,443 participants diagnosed with cancer, with age range 18-75 years. Dietary change was assessed <1-5 years before diagnosis and up to 12 years post-diagnosis. Meta-analyses showed that the standard mean difference (SMD) for energy (SMD-0.32, 95% confidence interval = -0.46 to -0.17) and carbohydrate consumption (SMD 0.20, 95% confidence interval = -0.27 to -0.14). Studies showed inconsistent findings for fat, protein and fibre, most food groups, and supplement intake. A small decrease in red and processed meat consumption was consistently reported. CONCLUSIONS: All studies reported some positive changes in dietary intake and supplement consumption after receiving a cancer diagnosis without any intervention. However, differences for food groups and nutrients were mainly small and not necessarily clinically meaningful. Evidence demonstrates that a cancer diagnosis alone is insufficient to motivate people to change their dietary intake, indicating that most people would benefit from a dietary intervention to facilitate change.

Flexible transition timing in discrete-time multistate life tables using Markov chains with rewards.

Discrete-time multistate life tables are attractive because they are easier to understand and apply in comparison with their continuous-time counterparts. While such models are based on a discrete time grid, it is often useful to calculate derived magnitudes (e.g. state occupation times), under assumptions which posit that transitions take place at other times, such as mid-period. Unfortunately, currently available models allow very few choices about transition timing. We propose the use of Markov chains with rewards as a general way of incorporating information on the timing of transitions into the model. We illustrate the usefulness of rewards-based multistate life tables by estimating working life expectancies using different retirement transition timings. We also demonstrate that for the single-state case, the rewards approach matches traditional life-table methods exactly. Finally, we provide code to replicate all results from the paper plus R and Stata packages for general use of the method proposed.

Methods for Constructing Normalised Reference Scores: An Application for Assessing Child Development at 24 Months of Age.

The use of the lambda-mu-sigma (LMS) method for estimating centiles and producing reference ranges has received much interest in clinical practice, especially for assessing growth in childhood. However, this method may not be directly applicable where measures are based on a score calculated from question response categories that is bounded within finite intervals, for example, in psychometrics. In such cases, the main assumption of normality of the conditional distribution of the transformed response measurement is violated due to the presence of ceiling (and floor) effects, leading to biased fitted centiles when derived using the common LMS method. This paper describes the methodology for constructing reference intervals when the response variable is bounded and explores different distribution families for the centile estimation, using a score derived from a parent-completed assessment of cognitive and language development in 24 month-old children. Results indicated that the z-scores, and thus the extracted centiles, improved when kurtosis was also modeled and that the ceiling effect was addressed with the use of the inflated binomial distribution. Therefore, the selection of the appropriate distribution when constructing centile curves is crucial.