The arithmetic of growth: Methods of calculation

This is a tutorial on the relations between population data and the rates of growth that are calculated from the data. For the calculation of rates of growth, discrete and continuous compounding will be compared so that the reader can see the reasons for using the mathematics of continuous compounding, which is the mathematics of exponential growth. Some properties of exponential growth are developed. Semi-logarithmic graphs will be discussed as a device for representing the size of growing populations and for analyzing the nature of the growth. Illustrative examples will be worked out in order to emphasize applications and utility.     

Enclosed versus open nursing stations in adult acute care psychiatric settings: does the design affect the therapeutic milieu?

Specific efforts by hospital accreditation organizations encourage renovation of nursing stations, so nurses can better see, attend, and care for their patients. The purpose of this study was to examine the effect of nursing station design on the therapeutic milieu in an adult acute care psychiatric unit. A repeated cross-sectional, pretest-posttest design was used. Data were collected from a convenience sample of 81 patients and 25 nursing staff members who completed the Ward Atmosphere Scale. Pretest data were collected when the unit had an enclosed nursing station, and posttest data were collected after renovations to the unit created an open nursing station. No statistically significant differences were found in patient or staff perceptions of the therapeutic milieu. No increase in aggression toward staff was found, given patients' ease of access to the nursing station. More research is needed about the impact of unit design in acute care psychiatric settings.     

Private Bag: Regionwide Planning Will Make the Problems Worse

Population and Environment -     

‘I shouldn’t be living there because I am a sponger’: negotiating everyday geographies by people with learning disabilities

Learning disability policy has for some time been framed by the goal of inclusion which purports to enable people with learning disabilities to lead a ‘life like any other’ person. This article examines the extent to which this is the case in England, by tracing the lived experiences of people with learning disabilities within their communities. The article draws on two interlinked qualitative studies involving interviews that examined their local place-based experiences of inclusion and exclusion. The findings reveal ‘moments of inclusion’ and opportunities for social encounter from peer support, but these were situated amidst wider experiences of exclusion and harassment.     

Teaching Children With Autism Spectrum Disorder to Report Past Behavior With the Use of a Speech-Generating Device

The Analysis of Verbal Behavior -     

Estimation for a first-order bifurcating autoregressive process with heavy-tail innovations

Asymptotics of an alternative extreme-value estimator for the autocorrelation parameter in a first-order bifurcating autoregressive (BAR) process with non-gaussian innovations are derived. This contrasts with traditional estimators whose asymptotic behavior depends on the central part of the innovation distribution. Within any BAR model, the main concern is addressing the complex dependency between generations. The inability of traditional methods to handle this dependency motivated an alternative procedure. With the combination of an extreme-value approach and a clever blocking argument, the dependency issue within the BAR process was resolved, which in turn allowed us to derive the limiting distribution for the proposed estimator through the use of regular variation and non-stationary point processes. Finally, the implications of our extreme-value approach are discussed with an extensive simulation study that not only assesses the reliability of our proposed estimate but also presents the findings for a new estimator of an unknown location parameter θ and its implications.     

Rhetoric to action: a study of stakeholder perceptions of aging well in two local communities

This qualitative study of local perceptions of policy goals and action in relation to aging reports 31 stakeholder interviews within 2 Australian communities exploring (a) the meaning of aging well; and (b) preferred policy actions to achieve positive aging outcomes. Findings suggest that community perceptions of aging well are broadly consistent with the goals of national and international policy frameworks in focusing on 3 dimensions--health, social engagement, and security. Further, participants believe that achievement of positive aging outcomes requires a mix of self-help, community action, and government intervention--particularly government support and encouragement for aging well initiatives.     

Covariate adjustment and estimation of mean response in randomised trials

Analyses of randomised trials are often based on regression models which adjust for baseline covariates, in addition to randomised group. Based on such models, one can obtain estimates of the marginal mean outcome for the population under assignment to each treatment, by averaging the model‐based predictions across the empirical distribution of the baseline covariates in the trial. We identify under what conditions such estimates are consistent, and in particular show that for canonical generalised linear models, the resulting estimates are always consistent. We show that a recently proposed variance estimator underestimates the variance of the estimator around the true marginal population mean when the baseline covariates are not fixed in repeated sampling and provide a simple adjustment to remedy this. We also describe an alternative semiparametric estimator, which is consistent even when the outcome regression model used is misspecified. The different estimators are compared through simulations and application to a recently conducted trial in asthma.