Imputation of Missing Covariates in Randomized Controlled Trials with Continuous Outcomes: Simple, Unbiased and Efficient Methods.

The literature on dealing with missing covariates in nonrandomized studies advocates the use of sophisticated methods like multiple imputation (MI) and maximum likelihood (ML)-based approaches over simple methods. However, these methods are not necessarily optimal in terms of bias and efficiency of treatment effect estimation in randomized studies, where the covariate of interest (treatment group) is independent of all baseline (pre-randomization) covariates due to randomization. This has been shown in the literature, but only for missingness on a single baseline covariate. Here, we extend the situation to multiple baseline covariates with missingness and evaluate the performance of MI and ML compared with simple alternative methods under various missingness scenarios in RCTs with a quantitative outcome. We first derive asymptotic relative efficiencies of the simple methods under the missing completely at random (MCAR) scenario and then perform a simulation study for non-MCAR scenarios. Finally, a trial on chronic low back pain is used to illustrate the implementation of the methods. The results show that all simple methods give unbiased treatment effect estimation but with increased mean squared residual. It also turns out that mean imputation and the missing-indicator method are most efficient under all covariate missingness scenarios and perform at least as well as MI and LM in each scenario.

Effectiveness of an integrated multidisciplinary geriatric rehabilitation programme for older persons with stroke: a multicentre randomised controlled trial.

BACKGROUND: Almost half of the stroke patients admitted to geriatric rehabilitation has persisting problems after discharge. Currently, there is no evidence based geriatric rehabilitation programme available for older stroke patients, combining inpatient rehabilitation with adequate ambulatory aftercare in the community. Therefore, we developed an integrated multidisciplinary rehabilitation programme that includes aftercare for older persons with stroke. We evaluated the effectiveness of this newly developed rehabilitation programme in comparison to usual care. METHODS: A multicentre randomised controlled trial was conducted in eight geriatric rehabilitation stroke units and their collaborating partners in primary care. The study population involved stroke patients and their informal caregivers who were aged 65 or over, living in the community before admission to geriatric rehabilitation, and expected to be able to return home after discharge. The programme consisted of three modules: inpatient neurorehabilitation, home-based self-management training, and stroke education. For patients, daily activity (FAI) was assessed as primary outcome and functional dependence (Katz-15), perceived quality of life (SSQoL) and social participation (IPA) as secondary outcomes. Additionally, among informal caregivers perceived care burden (self-rated burden VAS), objective care burden (Erasmus iBMG), and quality of life (CarerQol), were assessed as secondary outcomes. RESULTS: In total 190 patients and 172 informal caregivers were included. Mean age of the patients in the intervention group was 78.9 years (SD = 7.0) and in the usual care group 79.0 years (SD = 6.5). Significant favourable effects for the programme were observed for the subscale autonomy outdoors of the IPA (- 2.15, P = .047, and for the informal caregivers perceived care burden (1.23, P = .048. For the primary outcome daily activity and the other secondary outcomes, no significant effects were observed. CONCLUSION: The integrated multidisciplinary programme had no effect on daily activity of older stroke patients. However, patients participating in the programme had a higher level of perceived autonomy of outdoor activities and their informal caregivers perceived a lower care burden. The programme might be promising in providing adequate (after) care, although adaptation of the programme is recommended to increase its feasibility and improve its effects. TRIAL REGISTRATION: Current Controlled Trials ISRCTN62286281 . Registered 19-3-2010.

Factors associated with successful home discharge after inpatient rehabilitation in frail older stroke patients.

BACKGROUND: Stroke is a highly prevalent disease among older people and can have a major impact on daily functioning and quality of life. When community-dwelling older people are hospitalized due to stroke, discharge to an intermediate care facility for geriatric rehabilitation is indicated when return to the previous living situation is expected but not yet possible. However, a substantial proportion is still unable to return home after discharge and has to be admitted to a residential care setting. This study aims to identify which factors are associated with home discharge after inpatient rehabilitation among frail and multimorbid older stroke patients. METHODS: This study is a longitudinal cohort study among 92 community-dwelling stroke patients aged 65 years or over. All patients were admitted to one of eight participating intermediate care facilities for geriatric rehabilitation, under the expectation to return home after rehabilitation. We examined whether 16 potentially relevant factors (age; sex; household situation before admission; stroke history; cardiovascular disorders; diabetes mellitus; multimorbidity; cognitive disability; neglect; apraxia; dysphagia; urinary and bowel incontinence; emotional problems; sitting balance; daily activity level; and independence in activities of daily living) measured at admission were associated with discharge to the former living situation. Logistic regression analysis was used for statistical analysis. RESULTS: Mean age of the patients was 79.0 years (SD 6.4) and 51.1% was female. A total of 71 patients (77.1%) were discharged to the former living situation within 6 months after the start of geriatric rehabilitation. Of the 16 factors analysed, only a higher level of independence in activities of daily living at admission was significantly associated with home discharge. CONCLUSIONS: Our study shows that the vast majority of previously identified factors predicting home discharge among stroke patients, could not predict home discharge among a group of frail and multimorbid older persons admitted to geriatric rehabilitation. Only a higher level of independence in activities of daily living at admission was significantly related to home discharge. Additional insight in other factors that might predict home discharge after geriatric rehabilitation among this specific group of frail older stroke patients, is needed. TRIAL REGISTRATION: ISRCTN ISRCTN62286281. Registered 19-3-2010.

Imputation of missing covariate in randomized controlled trials with a continuous outcome: Scoping review and new results.

In this article, we first review the literature on dealing with missing values on a covariate in randomized studies and summarize what has been done and what is lacking to date. We then investigate the situation with a continuous outcome and a missing binary covariate in more details through simulations, comparing the performance of multiple imputation (MI) with various simple alternative methods. This is finally extended to the case of time-to-event outcome. The simulations consider five different missingness scenarios: missing completely at random (MCAR), at random (MAR) with missingness depending only on the treatment, and missing not at random (MNAR) with missingness depending on the covariate itself (MNAR1), missingness depending on both the treatment and covariate (MNAR2), and missingness depending on the treatment, covariate and their interaction (MNAR3). Here, we distinguish two different cases: (1) when the covariate is measured before randomization (best practice), where only MCAR and MNAR1 are plausible, and (2) when it is measured after randomization but before treatment (which sometimes occurs in nonpharmaceutical research), where the other three missingness mechanisms can also occur. The proposed methods are compared based on the treatment effect estimate and its standard error. The simulation results suggest that the patterns of results are very similar for all missingness scenarios in case (1) and also in case (2) except for MNAR3. Furthermore, in each scenario for continuous outcome, there is at least one simple method that performs at least as well as MI, while for time-to-event outcome MI is best.

Relative efficiencies of two-stage sampling schemes for mean estimation in multilevel populations when cluster size is informative.

In multilevel populations, there are two types of population means of an outcome variable ie, the average of all individual outcomes ignoring cluster membership and the average of cluster-specific means. To estimate the first mean, individuals can be sampled directly with simple random sampling or with two-stage sampling (TSS), that is, sampling clusters first, and then individuals within the sampled clusters. When cluster size varies in the population, three TSS schemes can be considered, ie, sampling clusters with probability proportional to cluster size and then sampling the same number of individuals per cluster; sampling clusters with equal probability and then sampling the same percentage of individuals per cluster; and sampling clusters with equal probability and then sampling the same number of individuals per cluster. Unbiased estimation of the average of all individual outcomes is discussed under each sampling scheme assuming cluster size to be informative. Furthermore, the three TSS schemes are compared in terms of efficiency with each other and with simple random sampling under the constraint of a fixed total sample size. The relative efficiency of the sampling schemes is shown to vary across different cluster size distributions. However, sampling clusters with probability proportional to size is the most efficient TSS scheme for many cluster size distributions. Model-based and design-based inference are compared and are shown to give similar results. The results are applied to the distribution of high school size in Italy and the distribution of patient list size for general practices in England.

Professional and family caregivers' attitudes towards involuntary treatment in community-dwelling people with dementia.

AIMS: The aim of this study was to gain insight into professional and family caregivers' attitudes towards involuntary treatment in community-dwelling people with dementia (PwD). BACKGROUND: The number of PwD with complex care needs living at home is increasing rapidly. In some situations, caregivers provide care against the will of PwD, referred to as involuntary treatment, which includes non-consensual care, psychotropic medication and physical restraints. DESIGN: A cross-sectional study. METHODS: A total of 228 professional (nursing staff, general practitioners (GPs) and other healthcare professionals such as physical therapists and psychologists) and 77 family caregivers of PwD completed the Maastricht Attitude Questionnaire-Home Care. This questionnaire measures attitudes towards involuntary treatment and perceived restrictiveness of and experienced discomfort in using involuntary treatment. Data were collected in the Netherlands between June and November 2016. RESULTS: Family caregivers and GPs had more positive attitudes towards involuntary treatment than nursing staff and other healthcare professionals, indicating that they are more accepting of involuntary treatment. A more positive attitude was associated with higher perceived caregiver burden and being a family caregiver. Family caregivers and GPs found the use of involuntary treatment less restrictive and indicated feeling more comfortable when using these measures. CONCLUSION: It is important to account for the differences in attitudes and foster dialogue among professional and family caregivers to find common ground about alternatives to involuntary treatment. These results will inform the development of an intervention that aims to prevent involuntary treatment in home care.

The effectiveness of an integrated care pathway in geriatric rehabilitation among older patients with complex health problems and their informal caregivers: a prospective cohort study.

BACKGROUND: To improve continuity and coordination of care in geriatric rehabilitation, an integrated care pathway was developed and implemented in The Netherlands. The purpose of this study was to assess the effects of this pathway on patients and informal caregivers. METHODS: Two cohorts of patients and their informal caregivers were prospectively recruited before implementation of the pathway (2011-2012) and after implementation of the pathway (2013-2014). Primary outcome measures were dependence in activities of daily living in patients (KATZ-15) and self-rated burden among informal caregivers (SRB-VAS). Secondary outcome measures were the frequency of performing extended daily activities, social participation, psychological well-being, quality of life and discharge location (patients) and quality of life and objective care burden (informal caregivers). Outcomes were measured at baseline, after three and after nine months. RESULTS: No effect was shown on the KATZ-15 after three and nine months. However, a larger percentage of patients were discharged home in the care pathway cohort (83% vs 58.1% after three months and 88.6% vs 67.4% after nine months; p = 0.004). Furthermore, after three months, patients from the care pathway cohort performed more extended daily activities (p = 0.014) and informal caregivers experienced a lower self-rated burden (p = 0.05). After nine months, these effects disappeared. No differences were found for the other outcome measures. CONCLUSIONS: Due to the positive effects of the integrated care pathway, we are inclined to recommend implementing the care pathway in regular care. To have longer lasting effects among patients and informal caregivers, we suggest actively disseminating information about the pathway to primary care providers who are currently still unaware of its content. TRIAL REGISTRATION: ISRCTN90000867 (date of registration: 07-04-2016).

Estimated Glomerular Filtration Rate and Albuminuria Are Associated with Biomarkers of Cardiac Injury in a Population-Based Cohort Study: The Maastricht Study.

BACKGROUND: Chronic kidney disease (CKD) is associated with an increased cardiovascular disease mortality risk. It is, however, less clear at what point in the course from normal kidney function to CKD the association with cardiovascular disease appears. Studying the associations of estimated glomerular filtration rate (eGFR) and albuminuria with biomarkers of (subclinical) cardiac injury in a population without substantial CKD may clarify this issue. METHODS: We examined the cross-sectional associations of eGFR and urinary albumin excretion (UAE) with high-sensitivity cardiac troponin (hs-cTn) T, hs-cTnI, and N-terminal probrain natriuretic-peptide (NT-proBNP) in 3103 individuals from a population-based diabetes-enriched cohort study. RESULTS: After adjustment for potential confounders, eGFR and UAE were associated with these biomarkers of cardiac injury, even at levels that do not fulfill the CKD criteria. For example, eGFR 60-<90 mL · min-1 ·(1.73 m2)-1 [vs ≥90 mL · min-1 · (1.73 m2)-1] was associated with a [ratio (95% CI)] 1.21 (1.17-1.26), 1.14 (1.07-1.20), and 1.19 (1.12-1.27) times higher hs-cTnT, hs-cTnI, and NT-proBNP, respectively. The association of eGFR with hs-cTnT was statistically significantly stronger than that with hs-cTnI. In addition, UAE 15-<30 mg/24 h (vs <15 mg/24 h) was associated with a 1.04 (0.98-1.10), 1.08 (1.00-1.18), and 1.07 (0.96-1.18) times higher hs-cTnT, hs-cTnI, and NT-proBNP, respectively. CONCLUSIONS: eGFR and albuminuria were already associated with biomarkers of (subclinical) cardiac injury at levels that do not fulfill the CKD criteria. Although reduced renal elimination may partly underlie the associations of eGFR, these findings support the concept that eGFR and albuminuria are, over their entire range, associated with cardiac injury.

Quality of care and quality of life of people with dementia living at green care farms: a cross-sectional study.

BACKGROUND: Many countries are introducing smaller, more home-like care facilities that represent a radically new approach to nursing home care for people with dementia. The green care farm is a new type of nursing home developed in the Netherlands. The goal of this study was to compare quality of care, quality of life and related outcomes in green care farms, regular small-scale living facilities and traditional nursing homes for people with dementia. METHODS: A cross-sectional design was used. Three types of nursing homes were included: (1) green care farms; (2) regular small-scale living facilities; (3) traditional nursing homes. All participating nursing homes were non-profit, collectively funded nursing homes in the south of the Netherlands. One hundred and fifteen residents with a formal diagnosis of dementia were included in the study. Data on quality of care was gathered and consisted of outcome indicators (e.g. falling incidents, pressure ulcers), structure indicators (e.g. hours per resident per day), and process indicators (e.g. presence, accessibility and content of protocols on care delivery). Furthermore, questionnaires on cognition, dependence in activities of daily living, quality of life, social engagement, neuropsychiatric symptoms, agitation, and depression were used. RESULTS: Data showed that quality of care was comparable across settings. No large differences were found on clinical outcome measures, hours per resident per day, or process indicators. Higher quality of life scores were reported for residents of green care farms in comparison with residents of traditional nursing homes. They scored significantly higher on the Quality of Life - Alzheimer's disease Scale (p < 0.05, ES = 0.8) indicating a better quality of life. In addition, residents of green care farms scored higher on three quality of life domains of the Qualidem: positive affect, social relations and having something to do (p < 0.05, ES > 0.7). No differences with regular small-scale living facilities were found. CONCLUSIONS: Green care farms seem to be a valuable alternative to existing nursing homes. This is important as people with dementia are a heterogeneous group with varying needs. In order to provide tailored care there also is a need for a variety of living environments.

Relationship between the presence of baccalaureate-educated RNs and quality of care: a cross-sectional study in Dutch long-term care facilities.

BACKGROUND: Recent evidence suggests that an increase in baccalaureate-educated registered nurses (BRNs) leads to better quality of care in hospitals. For geriatric long-term care facilities such as nursing homes, this relationship is less clear. Most studies assessing the relationship between nurse staffing and quality of care in long-term care facilities are US-based, and only a few have focused on the unique contribution of registered nurses. In this study, we focus on BRNs, as they are expected to serve as role models and change agents, while little is known about their unique contribution to quality of care in long-term care facilities. METHODS: We conducted a cross-sectional study among 282 wards and 6,145 residents from 95 Dutch long-term care facilities. The relationship between the presence of BRNs in wards and quality of care was assessed, controlling for background characteristics, i.e. ward size, and residents' age, gender, length of stay, comorbidities, and care dependency status. Multilevel logistic regression analyses, using a generalized estimating equation approach, were performed. RESULTS: 57% of the wards employed BRNs. In these wards, the BRNs delivered on average 4.8 min of care per resident per day. Among residents living in somatic wards that employed BRNs, the probability of experiencing a fall (odds ratio 1.44; 95% CI 1.06-1.96) and receiving antipsychotic drugs (odds ratio 2.15; 95% CI 1.66-2.78) was higher, whereas the probability of having an indwelling urinary catheter was lower (odds ratio 0.70; 95% CI 0.53-0.91). Among residents living in psychogeriatric wards that employed BRNs, the probability of experiencing a medication incident was lower (odds ratio 0.68; 95% CI 0.49-0.95). For residents from both ward types, the probability of suffering from nosocomial pressure ulcers did not significantly differ for residents in wards employing BRNs. CONCLUSIONS: In wards that employed BRNs, their mean amount of time spent per resident was low, while quality of care on most wards was acceptable. No consistent evidence was found for a relationship between the presence of BRNs in wards and quality of care outcomes, controlling for background characteristics. Future studies should consider the mediating and moderating role of staffing-related work processes and ward environment characteristics on quality of care.

Diurnal Rhythm of Cardiac Troponin: Consequences for the Diagnosis of Acute Myocardial Infarction.

BACKGROUND: Interpretation of serial high-sensitivity cardiac troponin (hs-cTn) measurements for the diagnosis of acute myocardial infarction (AMI) assumes random fluctuation of hs-cTn around an individual's homeostatic set point. The aim of this study was to challenge this diagnostic concept. METHODS: Study 1 examined the presence of a diurnal hs-cTn rhythm by hourly blood sampling, day and night, in 24 individuals without a recent history of AMI. Study 2 assessed morning vs evening diagnostic accuracy of hs-cTnT and hs-cTnI in a prospective multicenter diagnostic study of 2782 unselected patients, presenting to the emergency department with acute chest pain. RESULTS: In study 1, hs-cTnT, but not hs-cTnI, exhibited a diurnal rhythm, characterized by gradually decreasing concentrations throughout daytime, rising concentrations during nighttime, to peak concentrations in the morning (mean 16.2 ng/L at 8:30 AM and 12.1 ng/L at 7:30 PM). In study 2, the hs-cTnT rhythm was confirmed by higher hs-cTnT concentrations in early-morning presenters compared to evening presenters with an adjudicated diagnosis of noncardiac disease. The diagnostic accuracy [area under the receiver-operation characteristics curve (AUC)] of hs-cTnT at presentation, 1 h, and for the combination of absolute changes with presenting concentration, were very high and comparable among patients presenting early morning as compared to evening (all AUC >0.93). hs-cTnI exhibited no diurnal rhythm with no differences in AUC among early-morning and evening presenters. CONCLUSIONS: Rhythmic diurnal variation of hs-cTnT is a general phenomenon that is not seen with hs-cTnI. While the diurnal hs-cTnT rhythm does not seem to affect the diagnostic accuracy of hs-cTnT for AMI, it should be considered when using hs-cTnT for screening purposes. CLINICAL TRIAL REGISTRATION: 1. Circadian Variation of Cardiac Troponin, NCT02091427, www.clinicaltrials.gov/ct2/show/NCT02091427. 2. Advantageous Predictors of Acute Coronary Syndrome Evaluation (APACE) Study, NCT00470587, www.clinicaltrials.gov/ct2/show/NCT00470587.

The association between aspects of daily life and quality of life of people with dementia living in long-term care facilities: a momentary assessment study.

BACKGROUND: To improve the quality of life (QoL) of people with dementia (PwD) living in long-term care facilities, insight into the association between QoL and how people spend their daily lives is urgently needed. This study investigated which aspects of daily life are related to QoL in dementia. METHODS: An observational study was conducted. Daily life was assessed with the tablet-based Maastricht Electronic Daily Life Observation-tool (MEDLO-tool). Aspects included activity, engagement in the activity, social interaction, physical effort, mood, and agitation. QoL was assessed by formal nursing caregivers using the Quality of Life-Alzheimer's Disease scale (QoL-AD). A total of 9,660 momentary assessments were conducted. RESULTS: The mean age of the 115 participants was 84 years and most (75%) were women. Bivariate analyses showed that residents with a higher QoL carried out less passive/purposeless activities (25% vs. 38%), were more engaged in active, expressive, and social activities, (40% vs. 27%), had more social interaction (34% vs. 22%), and had better mood scores (scale 1-7, 5.0 vs. 4.8), compared with residents with a lower QoL (all p-values < 0.001). Multivariate analyses showed that having more social interaction and a positive mood are related to a higher QoL. CONCLUSIONS: The results underline the importance of social interaction and a positive mood for a higher QoL. Future research should investigate the importance of engagement in activities in more detail.

Growth and endothelial function in the first 2 years of life.

OBJECTIVE: To test the hypothesis that the inverse association between infant growth and endothelial function at 6 months would persist to 24 months and that accelerated growth would lead to an increased percent body fat, which would, in turn, impact negatively on endothelial function. STUDY DESIGN: In a prospective observational study, 104 healthy term newborns underwent anthropometry and measurements of vascular vasodilation at 0, 6, 12, and 24 months. We recorded maximum vasodilation in response to acetylcholine (endothelium-dependent) and nitroprusside (endothelium-independent) by use of laser-Doppler vascular perfusion monitoring of the forearm skin vasculature. Additional anthropometry at 1 and 3 months was collected from child welfare centers. The data were analyzed by multilevel linear regression. RESULTS: Weight gain from 0-1 month was associated inversely with maximum perfusion in response to acetylcholine at the age of 2 years (b = -8.28 perfusion units [PU] per Δ z-score, P = .03). Weight gain from 0-1 month was related positively to maximum perfusion in response to nitroprusside (b = 10.12 PU per Δ z-score, P = .04), as was birth weight (b = 8.02 PU per z-score, P = .02). Body fat percentage did not have a significant effect in any of the perfusion models and was not related to maximum perfusion at 2 years. CONCLUSION: Infant weight gain from 0-1 month is inversely related to endothelial function in healthy term infants, at least to the age of 2 years. This relationship was not explained by an increased percentage body fat.

Heart failure in nursing home residents; a cross-sectional study to determine the prevalence and clinical characteristics.

BACKGROUND: Heart failure (HF) is expected to be highly prevalent in nursing home residents, but precise figures are scarce. The aim of this study was to determine the prevalence of HF in nursing home residents and to get insight in the clinical characteristics of residents with HF. METHODS: The study followed a multi-centre cross-sectional design. Nursing home residents (n = 501) in the southern part of the Netherlands aged over 65 years and receiving long-term somatic or psychogeriatric care were included in the study. The diagnosis of HF and related characteristics were based on data collected from actual clinical examinations (including history, physical examination, ECG, cardiac markers and echocardiography), patient records and questionnaires. A panel of two cardiologists and a geriatrician ultimately judged the data to diagnose HF. RESULTS: The overall prevalence of HF in nursing home residents was 33 %, of which 52 % had HF with preserved ejection fraction. The symptoms dyspnoea and oedema and a cardiac history were more common in residents with HF. Diabetes mellitus, chronic obstructive pulmonary disease (COPD) were also more prevalent in those with HF. Residents with HF had a higher score on the Mini Mental State Examination. 54 % of those with HF where not known before, and in 31 % with a history of HF, this diagnosis was not confirmed by the expert panel. CONCLUSION: This study shows that HF is highly prevalent in nursing home residents with many unknown or falsely diagnosed with HF. Equal number of HF patients had reduced and preserved left-ventricular ejection fraction. TRIAL REGISTRATION: The Netherlands National Trial Register NTR2663 (27-12-2010).

Maternal but not fetal FADS gene variants modify the association between maternal long-chain PUFA intake in pregnancy and birth weight.

Several studies have shown a positive association between maternal fish intake in pregnancy and pregnancy duration and child birth weight (BW), probably due to fish n-3 (ω-3) long-chain polyunsaturated fatty acids (LC-PUFAs). n-3 LC-PUFAs can also be synthesized endogenously, and their synthesis depends on single nucleotide polymorphisms (SNPs) in the fatty acid desaturase (FADS) gene encoding for FADS. We assessed the associations of maternal docosahexaenoic acid (DHA) intake in pregnancy with pregnancy duration and BW and investigated whether these associations are modified by maternal or fetal FADS SNP genotypes. We hypothesized that we would find stronger associations in minor allele homozygous mothers or fetuses due to their lower n-3 LC-PUFA endogenous synthesis and hence higher dependence on dietary supply. Data on maternal diet, pregnancy duration, and BW were available for 2622 mother-child pairs from the KOALA (Kind, Ouders en gezondheid: Aandacht voor Leefstijl en Aanleg) Birth Cohort Study. The rs174556 FADS SNP was genotyped in 1516 mothers and 1515 children. Associations and gene-diet interactions were tested with linear regression adjusting for potential confounders, including intake of other PUFAs. Women at the 75th percentile of DHA intake had 0.7-d longer pregnancies (P = 0.016) and 28-g heavier infants (P = 0.039) than did women at the 25th percentile of intake. Associations with arachidonic acid intake were of the same order but in the opposite direction. Mothers who were homozygous for the minor allele had 2-d shorter pregnancies (P = 0.035) and infants who were nearly 140 g lighter (P = 0.006) than did mothers who were major allele homozygotes. Post hoc analyses revealed that they had higher prepregnancy BMI (P = 0.020). Among the women homozygous for the minor allele, those at the 75th percentile of DHA intake had 226-g heavier infants than those at the 25th percentile of intake (P = 0.030), whereas DHA intake was not significantly associated with BW in major allele carriers. These findings suggest that maternal and fetal fatty acid requirements during pregnancy depend on maternal genetic variation in LC-PUFA synthesis.

Sample size calculation and optimal design for regression-based norming of tests and questionnaires.

To prevent mistakes in psychological assessment, the precision of test norms is important. This can be achieved by drawing a large normative sample and using regression-based norming. Based on that norming method, a procedure for sample size planning to make inference on Z-scores and percentile rank scores is proposed. Sampling variance formulas for these norm statistics are derived and used to obtain the optimal design, that is, the optimal predictor distribution, for the normative sample, thereby maximizing precision of estimation. This is done under five regression models with a quantitative and a categorical predictor, differing in whether they allow for interaction and nonlinearity. Efficient robust designs are given in case of uncertainty about the regression model. Furthermore, formulas are provided to compute the normative sample size such that individuals' positions relative to the derived norms can be assessed with prespecified power and precision. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Passive movement therapy in severe paratonia: a multicenter randomized clinical trial.

BACKGROUND: Paratonia causes severe movement dysfunction in late stage dementia. Passive Movement Therapy (PMT) is often used to decrease high muscle tone, but the efficacy has never been shown. The objective of this study is to investigate the effect of PMT on muscle tone after two and four weeks of treatment. METHODS: This study comprised a multicenter single-blinded RCT. Nursing home residents with dementia (according to the DSM-IV-TR criteria) and moderate to severe paratonia were randomly assigned to either a PMT or control group. The PMT group received PMT three times a week over four weeks. The control group received no PMT. The primary outcome was the severity of paratonia as measured by the Modified Ashworth scale (MAS). Secondary outcomes were clinical change (Clinical Global Impression; CGI), caregiver's burden (modified patient specific complaints; PSC), and level of pain during morning care (Pain Assessment Checklist for Elderly with Limited Ability to Communicate, Dutch version; PACSLAC-D). All outcomes were assessed at baseline and after two and four weeks. The MAS, PACSLAC-D, and PSC data were subjected to multilevel mixed linear analysis, and the CGI data to cross-tabulation χ2 analysis. RESULTS: One-hundred-and-one patients from 12 Dutch nursing homes participated in the study; data from 47 patients in the PME group and 54 controls were analyzed. Patients receiving PMT performed no better in paratonia assessments, nor on CGI, PSC, or PACSLAC-D, than controls in two and four week's time. CONCLUSION: PMT has no beneficial effects and should therefore not be recommended as an intervention in severe paratonia. TRIAL REGISTRATION: Current Controlled Trials ISRCTN43069940.

The prevalence and management of heart failure in Dutch nursing homes; design of a multi-centre cross-sectional study.

BACKGROUND: Heart failure is likely to be particularly prevalent in the nursing home population, but reliable data about the prevalence of heart failure in nursing homes are lacking. Therefore the aims of this study are to investigate (a) the prevalence and management of heart failure in nursing home residents and (b) the relation between heart failure and care dependency as well as heart failure and quality of life in nursing home residents. METHODS/DESIGN: Nursing home residents in the southern part of the Netherlands, aged over 65 years and receiving long-term somatic or psychogeriatric care will be included in the study. A panel of two cardiologists and a geriatrician will diagnose heart failure based on data collected from actual clinical examinations (including history, physical examination, ECG, cardiac markers and echocardiography), patient records and questionnaires. Care dependency will be measured using the Care Dependency Scale. To measure the quality of life of the participating residents, the Qualidem will be used for psychogeriatric residents and the SF-12 and VAS for somatic residents. CONCLUSION: The study will provide an insight into the actual prevalence and management of heart failure in nursing home residents as well as their quality of life and care dependency. TRIAL REGISTRATION: Dutch trial register NTR2663.

Material vs. psychosocial explanations of old-age educational differences in physical and mental functioning.

BACKGROUND: Taking into account our rapidly ageing population, older people are of particular interest in studying health inequalities. The aim of the present study is to examine the relation between socio-economic status and health-related functioning in older people and to find out how material factors (e.g. the lack of basic goods) and psychosocial factors (e.g. low self-efficacy) compare regarding the explanation of these socio-economic differences. METHODS: Data came from 5061 Dutch men and women aged ≥ 55 years who participated in the longitudinal Study on Medical Information and Lifestyles Eindhoven (SMILE) study. Baseline data were collected between November 2002 and May 2004 and respondents were followed until May 2009 (follow-up range: 0-5 years). Multilevel analyses were used to study the association between educational level and longitudinal changes in physical and mental functioning (i.e. two subscales of the SF-36) and to study the relative contribution of material and psychosocial factors to this relation. RESULTS: Low educational level was associated with poor initial physical and mental functioning. However, no further widening of these gradients was found during follow-up. Material factors reduced the initial educational differences by an average of 29%, whereas psychosocial factors, mastery and self-efficacy in particular, reduced these differences by an average of 60%. CONCLUSION: More than material factors, psychosocial factors, mastery and self-efficacy in particular, explained a large part of the educational differences in physical and mental functioning in older people. Further research is recommended to explore the amenability to change of characteristics that hamper people from taking control over their lives.

Prevalence, incidence and risk factors of paratonia in patients with dementia: a one-year follow-up study.

BACKGROUND: Paratonia is a progressive motor problem that is observed in individuals with dementia and is not a well-known phenomenon. This study explores the development and risk factors of paratonia in moderate stage dementia patients. METHODS: A multi-center, longitudinal, one-year follow-up cohort study was performed. Patients with an established diagnosis of dementia, with a score of 6 or lower on the Global Deterioration Scale (GDS) were included. The participants were assessed using the Paratonia Assessment Instrument (PAI), the Timed Up and GO test, the Qualidem, the Global Deterioration Scale (Reisberg et al., 1982) and the Mini-mental State Examination. Information about each patient's diagnosis of dementia, comorbidities and use of medication were obtained from the participant's medical file. The PAI was assessed every three months, the other variables at baseline and after 12 months. Cross-tabulation χ2 and logistic regression tests were used for the statistical analyses. RESULTS: Baseline measures were assessed in the 204 participants - 111 (54%) female and 93 (46%) male, with a mean age of 79.8 years (56-97). Seventy-one patients (34.8%) were diagnosed with paratonia at baseline, and 51 patients developed paratonia over one year. The highest hazard ratio (3.1) for developing paratonia within one year was observed in the vascular dementia group. The logistic regression analysis revealed that the presence of diabetes mellitus (OR = 10.7) was significantly related to the development of paratonia (Wald χ2 p-value < 0.01). CONCLUSIONS: Diabetes mellitus and likely vascular damage are risk factors for the development of paratonia.