A comparison of sustainability theory with UK and European airports policy and practice.

There are three main theoretical difficulties involved in relating sustainability to aviation, and which a research agenda for sustainable aviation needs to address. The first is uncertainty regarding the critical thresholds of global environmental systems. The second is a lack of protocols for allocating permissible environmental consumption shares to, and hence targets for, individual enterprises or sectors. The third is differing value judgements of what natural features should be sustained. For the time being, these difficulties preclude determination of the degree of sustainability or unsustainability of any individual airport with respect to global environmental systems. Nevertheless, at this stage it can at least be said that since most economic activity has an adverse environmental impact, airports with higher throughputs of material and people will tend to be less sustainable than smaller-scale airports given similar technologies and regulatory compliance. This is theoretically supported and illustrated with waste arising as an indicator at reviewed airports. Despite governmental policies of sustainable mobility, there is a disjunction between EU and UK policy on airports and individual airport practice, and environmental sustainability theory. In the UK and EU, airport practice and governmental policy is to mitigate the impacts of aviation, but not at the expense of its aviation growth. This mitigation practice is summarised for the reviewed airports and presented in a framework that accounts for the suggested, interim approach to sustainability assessment.

Effectiveness of medical nutrition therapy provided by dietitians in the management of non-insulin-dependent diabetes mellitus: a randomized, controlled clinical trial.

OBJECTIVE: To assess the effect of medical nutrition therapy (MNT) provided by dietitians on medical and clinical outcomes for adults with non-insulin-dependent diabetes mellitus (NIDDM), and to compare MNT administered according to practice guidelines nutrition care (PGC) to MNT administered with basic nutrition care (BC). DESIGN: A prospective, randomized, controlled clinical trial of two levels of MNT on metabolic control in persons newly diagnosed with or currently under treatment for NIDDM was conducted at diabetes centers in three states (Minnesota, Florida, and Colorado). BC consisted of a single visit with a dietitian; PGC involved an initial visit with a dietitian followed by two visits during the first 6 weeks of the study period. Data were collected at entry to the study and at 3 and 6 months. SUBJECTS: Results are reported for 179 men and women aged 38 to 76 years: 85 assigned randomly to BC and 94 to PGC. This represents 72% of the 247 subjects enrolled. An additional 62 adults with NIDDM at one site who had no contact with a dietitian were identified as a nonrandom comparison group. OUTCOMES: Medical outcome measures included fasting plasma glucose (FPG), glycated hemoglobin (HbA1c), and serum lipid levels. Clinical outcomes included weight, body mass index, waist-to-hip ratio, and changes in medical therapy. STATISTICAL ANALYSES: Initial analysis of the discrete variables was done using the chi 2 statistic with Yates' correction. Initial analysis of continuous variables was done by analysis of variance. The changes in variables between time periods were analyzed by paired t test, and comparisons between groups were analyzed using a t test for independent groups. RESULTS: At 6 months, PGC resulted in significant improvements in blood glucose control as indicated by FPG and HbA1c levels and BC resulted in significant improvements in HbA1c level. Participants assigned to the PGC group had a mean FPG level at 6 months that was 10.5% lower than the level at entry, and those in the BC group had a 5.3% lower value. Among subjects who had diabetes for longer than 6 months, those who received PGC had a significantly better HbA1c level at 3 months compared with those receiving BC. The comparison group showed no improvement in glycemic control over a comparable 6 months. PGC subjects had significant improvements in cholesterol values at 6 months, and subjects in both the PGC and the BC groups had significant weight loss. CONCLUSIONS: MNT provided by dietitians resulted in significant improvements in medical and clinical outcomes in both the BC and PGC groups and is beneficial to persons with NIDDM. Persons with a duration of diabetes longer than 6 months tended to do better with PGC than with BC. Because of the upward trend in glucose levels after 3 months, ongoing MNT by dietitians is important for long-term metabolic control.

Cost-effectiveness of medical nutrition therapy provided by dietitians for persons with non-insulin-dependent diabetes mellitus.

OBJECTIVE: To conduct a cost analysis and cost-effectiveness study based on a randomized clinical trial of basic nutrition care (BC) and practice guidelines nutrition care (PGC) provided by dietitians in outpatient clinics. DESIGN: Subjects with non-insulin-dependent diabetes mellitus (NIDDM) from three states (Minnesota, Florida, Colorado) were randomly assigned to a group receiving BC or a group receiving PGC for a 6-month clinical trial. Along with data about medical and clinical outcomes, data about cost resources were collected. The cost-effectiveness of PGC compared with BC was calculated using per-patient costs and glycemic outcomes for the 6 months of the study. A net cost-effectiveness ratio comparing BC and PGC, including the cost savings resulting from changes in medical therapy, was also calculated. SUBJECTS: The study reports on a sample of 179 subjects with NIDDM between the ages of 38 and 76 years who completed the clinical trial. RESULTS: Patients in the PGC group experienced a mean 1.1 +/- 2.8 mmol/L decrease in fasting plasma glucose level 6 months after entry to the study, for a total per-patient cost of $112. PGC costs included one glycated hemoglobin assay used by the dietitian to evaluate nutrition outcomes. Patients in the BC group experienced a mean 0.4 +/- 2.7 mmol/L decrease, for a total per-patient cost of $42. In the PGC group, 17 persons had changes in therapy, which yielded an average 12-month cost savings prorated for all patients of $31.49. In contrast, in the BC group, 9 persons had changes in therapy, for an average 12-month prorated cost savings of $3.13. Each unit of change in fasting plasma glucose level from entry to the 6-month follow-up can be achieved with an investment of $5.75 by implementing BC or of $5.84 by implementing PGC. If net costs are considered (per-patient costs--cost savings due to therapy changes), the cost-effectiveness ratios become $5.32 for BC and $4.20 for PGC, assuming the medical changes in therapy were maintained for 12 months. APPLICATIONS: These findings suggest that individualized nutrition interventions can be delivered by experienced dietitians with a reasonable investment of resources. Cost-effectiveness is enhanced when dietitians are engaged in active decision making about intervention alternatives based on the patient's needs.