A simulation model for policy decision analysis: a case of pandemic influenza on a university campus.

Pandemic influenza preparedness plans strongly focus on efficient mitigation strategies including social distancing, logistics and medical response. These strategies are formed by multiple decision makers before a pandemic outbreak and during the pandemic in local communities, states and nation-wide. In this paper, we model the spread of pandemic influenza in a local community, a university, and evaluate the mitigation policies. Since the development of an appropriate vaccine requires a significant amount of time and available antiviral quantities can only cover a relatively small proportion of the population, university decision makers will first focus on non-pharmaceutical interventions. These interventions include social distancing and isolation. The disease spread is modelled as differential equations-based compartmental model. The system is simulated for multiple non-pharmaceutical interventions such as social distancing including suspending university operations, evacuating dorms and isolation of infected individuals on campus. Although the model is built based on the preparedness plan of one of the biggest universities in the world, Arizona State University, it can easily be generalized for other colleges and universities. The policies and the decisions are tested by several simulation runs and evaluations of the mitigation strategies are presented in the paper.

Pedometer accuracy in patients with chronic heart failure.

This study assesses the accuracy of the Omron HJ-720ITC pedometer at low walking intensities in patients with chronic heart failure. Step accuracy was assessed by visual observation on the treadmill and during free walking at 40, 50, 60, 70, 80 m/min, as well as during self paced walking using the 6 min walk test. A total of ninety-seven patients with heart failure (mean age: 61+/-13, NYHA I, N=30; NYHA II, N=32; NYHA III, N=35) participated in the study. At predefined walking speeds, a statistically significant % error in pedometer accuracy was evident at 60 m/min (p=0.039), and% error increased markedly below this threshold. Highest% error in pedometer accuracy was seen at 40 m/min (mean bias (% error): 28.3+/-9.0%; 95% CI: 21.8-34.7; p<0.001). During self paced walking (6MWT) the absolute% error in pedometer readings was largest in patients with strongest functional limitations and 6 MWT distances <400 m (mean bias (% error): 10.7+/-13.6%; CI 5.6-15.4, p<0.001). The Omron HJ-720ITC pedometer is accurate for monitoring activity in individuals with normal walking behaviour, but seems unsuitable for chronically ill patients characterised by slow walking gaits.

One year follow-up of overweight and obese hypertensive adults following intensive lifestyle therapy.

OBJECTIVE: To examine the long-term effect on weight maintenance and dietary habits of participants in a clinical trial for weight loss. SETTING: Community-based residents living in Maryland. PARTICIPANTS: Forty-four hypertensive, overweight adults who participated in a randomized clinical trial of weight loss. Participants were randomized to an intensive 'lifestyle' intervention or a 'monitoring' group. MAIN OUTCOME MEASURES: Weight, self-reported current intake of fat and fruit/fibre and self-reported barriers to maintain weight loss were assessed 1 year after the completion of the Diet, Exercise and Weight-loss Intervention Trial (DEW-IT) trial. ANALYSIS: t-tests were used to compare groups for differences in continuous variables and chi-square tests were used to compare groups for categorical variables. RESULTS: Fourty-two of the 44 DEW-IT subjects participated in the follow-up study. Overall, 55% (12/19) of the lifestyle intervention group remained at or below their baseline weight at 1 year, compared with 48% (11/23) of the monitoring group (P = 0.32). However, during that year, 95% (18/19) of the lifestyle intervention group and 52% (12/23) of the monitoring group gained weight from the end of the study. Both groups reported similar intake of fruits/vegetables (servings day(-1)), dietary fibre (g day(-1)) and fat (g day(-1)). CONCLUSIONS AND IMPLICATIONS: The majority of participants who lost weight during the trial regained weight during the course of 1 year. A successful intensive 2-month programme of lifestyle modification (DEW-IT) was ineffective for long-term maintenance of weight loss.