Factors influencing the pace of food intake for nursing home residents with dementia: Resident characteristics, staff mealtime assistance and environmental stimulation

AIM

To examine the association of resident characteristics, staff mealtime assistance and environmental stimulation with the pace of food intake.

DESIGN

A secondary analysis of 36 baseline eating videos involving 19 nursing assistants and 15 residents with dementia in eight nursing homes from a communication intervention study.

METHODS

The outcome variable was the pace of food intake (the number of bites and drinks per minute). The exploratory variables were resident characteristics (age, gender, dementia stage and eating performance), staff mealtime assistance (frequency of verbal, visual, partial and full physical assistance) and environmental stimulation. Multi-level models were used to examine the association.

RESULTS

A faster pace of food intake is associated with being male, better eating performance, staff provision of visual and physical assistance and better quality of environmental stimulation that involved interaction. The pace of food intake was not associated with resident age, staff verbal assistance or partial physical assistance.

An objective approach to model reduction: Application to the Sirius wheat model

An existing simulation model of wheat growth and development, Sirius, was evaluated through a systematic model reduction procedure. The model was automatically manipulated under software control to replace variables within the model structure with constants, individually and in combination. Predictions of the resultant models were compared to growth analysis observations of total biomass, grain yield, and canopy leaf area derived from 9 trials conducted in the UK and New Zealand under optimal, nitrogen limiting and drought conditions. Model performance in predicting these observations was compared in order to evaluate whether individual model variables contributed positively to the overall prediction. Of the 1 1 1 model variables considered 16 were identified as potentially redundant. Areas of the model where there was evidence of redundancy were: (a) translocation of biomass carbon to grain; (b) nitrogen physiology; (c) adjustment of air temperature for various modelled processes; (d) allowance for diurnal variation in temperature; (e) vernalisation (f) soil nitrogen mineralisation (g) soil surface evaporation. It is not suggested that these are not important processes in real crops, rather, that their representation in the model cannot be justified in the context of the analysis. The approach described is analogous to a detailed model inter-comparison although it would be better described as a model intra-comparison as it is based on the comparison of many simplified forms of the same model. The approach provides automation to increase the efficiency of the evaluation and a systematic means of increasing the rigour of the evaluation.