Impact of an integrated model of care on potentially preventable hospitalizations for people with Type 2 diabetes mellitus.

AIMS: To evaluate the impact of an integrated model of care for patients with complex Type 2 diabetes mellitus on potentially preventable hospitalizations. METHODS: A prospective controlled trial was conducted comparing a multidisciplinary, community-based, integrated primary-secondary care diabetes service with usual care at a hospital diabetes outpatient clinic. Study and hospital admissions data were linked for the period from 12 months before to 24 months after commencement of the trial. The primary outcome was the number of potentially preventable hospitalizations with diabetes-related principal diagnoses. Length of stay once hospitalized was also reported. RESULTS: Of 327 adult participants, 206 were hospitalized and accounted for 667 admissions during the study period. Compared with the usual care group, patients in the integrated model of care group were nearly half as likely to be hospitalized for a potentially preventable diabetes-related principal diagnosis in the 24 months after study commencement (incidence rate ratio 0.53, 95% CI 0.29, 0.96; P = 0.04). The magnitude of the result remained similar after adjusting for age, sex, education and baseline HbA1c concentration (incidence rate ratio 0.54, 95% CI 0.29, 1.01; P = 0.05).When hospitalized, patients in the integrated care group had a similar length of stay compared with those in the usual care group (median difference -2 days, 95% CI -6.5, 2.3; P = 0.33). CONCLUSIONS: Patients receiving the integrated model of care had a reduction in the number of hospitalizations when the principal diagnosis for admission was a diabetes-related complication. Integrated models of care for people with complex diabetes can reduce hospitalizations and help attempts to curtail increasing demand on finite health services.

A cost-effectiveness analysis of a telephone-linked care intervention for individuals with Type 2 diabetes.

AIM: To assess the cost-effectiveness of an automated telephone-linked care intervention, Australian TLC Diabetes, delivered over 6 months to patients with established Type 2 diabetes mellitus and high glycated haemoglobin level, compared to usual care. METHODS: A Markov model was designed to synthesize data from a randomized controlled trial of TLC Diabetes (n=120) and other published evidence. The 5-year model consisted of three health states related to glycaemic control: 'sub-optimal' HbA1c ≥58mmol/mol (7.5%); 'average' ≥48-57mmol/mol (6.5-7.4%) and 'optimal' <48mmol/mol (6.5%) and a fourth state 'all-cause death'. Key outcomes of the model include discounted health system costs and quality-adjusted life years (QALYS) using SF-6D utility weights. Univariate and probabilistic sensitivity analyses were undertaken. RESULTS: Annual medication costs for the intervention group were lower than usual care [ INTERVENTION: £1076 (95%CI: £947, £1206) versus usual care £1271 (95%CI: £1115, £1428) p=0.052]. The estimated mean cost for intervention group participants over five years, including the intervention cost, was £17,152 versus £17,835 for the usual care group. The corresponding mean QALYs were 3.381 (SD 0.40) for the intervention group and 3.377 (SD 0.41) for the usual care group. Results were sensitive to the model duration, utility values and medication costs. CONCLUSION: The Australian TLC Diabetes intervention was a low-cost investment for individuals with established diabetes and may result in medication cost-savings to the health system. Although QALYs were similar between groups, other benefits arising from the intervention should also be considered when determining the overall value of this strategy.

Model of care for the management of complex Type 2 diabetes managed in the community by primary care physicians with specialist support: an open controlled trial.

AIMS: To evaluate patient outcomes for a novel integrated primary/specialist model of community care for complex Type 2 diabetes mellitus management compared with outcomes for usual care at a tertiary hospital for diabetes outpatients. METHODS: This was a prospective open controlled trial performed in a primary and tertiary care setting in Australia. A total of 330 patients with Type 2 diabetes aged >18 years were allocated to an intervention (n=185) or usual care group (n=145). The intervention arm was a community-based model of care led by a general practitioner with advanced skills and an endocrinologist partnership. Usual care was provided via the hospital diabetes outpatient department. The primary end point was HbA(1c) concentration at 12 months. Secondary end points included serum lipids and blood pressure. RESULTS: The mean change in HbA1c concentration in the intervention group was -9 mmol/mol (-0.8%) at 12 months and in the usual care group it was -2 mmol/mol (-0.2%) (95% CI -5,1). The percentage of patients in the intervention group achieving the HbA(1c) target of ≤53 mmol/mol (7%) increased from 21 to 42% (P<0.001); for the usual care group there was a 1% increase to 39% of patients attaining this target (P=0.99). Patients in the intervention group experienced significant improvements in blood pressure and total cholesterol compared with those in the usual care group. The percentage of patients achieving clinical targets was greater in the intervention group for the combined target of HbA(1c) concentration, blood pressure and LDL cholesterol. CONCLUSIONS: A community-based, integrated model of complex diabetes care, delivered by general practitioners with advanced skills, produced clinical and process benefits compared with a tertiary diabetes outpatient clinic.

Visual sensitivity loss in the central 30° of visual field is associated with diabetic peripheral neuropathy.

AIMS/HYPOTHESIS: Impaired central vision has been shown to predict diabetic peripheral neuropathy (DPN). Several studies have demonstrated diffuse retinal neurodegenerative changes in diabetic patients prior to retinopathy development, raising the prospect that non-central vision may also be compromised by primary neural damage. We hypothesise that type 2 diabetic patients with DPN exhibit visual sensitivity loss in a distinctive pattern across the visual field, compared with a control group of type 2 diabetic patients without DPN. METHODS: Increment light sensitivity was measured by standard perimetry in the central 30° of visual field for two age-matched groups of type 2 diabetic patients, with and without neuropathy (n = 40/30). Neuropathy status was assigned using the neuropathy disability score. Mean visual sensitivity values were calculated globally, for each quadrant and for three eccentricities (0-10°, 11-20° and 21-30°). Data were analysed using a generalised additive mixed model (GAMM). RESULTS: Global and quadrant between-group visual sensitivity mean differences were marginally but consistently lower (by about 1 dB) in the neuropathy cohort compared with controls. Between-group mean differences increased from 0.36 to 1.81 dB with increasing eccentricity. GAMM analysis, after adjustment for age, showed these differences to be significant beyond 15° eccentricity and monotonically increasing. Retinopathy levels and disease duration were not significant factors within the model (p = 0.90). CONCLUSIONS/INTERPRETATION: Visual sensitivity reduces disproportionately with increasing eccentricity in type 2 diabetic patients with peripheral neuropathy. This sensitivity reduction within the central 30° of visual field may be indicative of more consequential loss in the far periphery.

Retinal nerve fibre layer thinning associated with diabetic peripheral neuropathy.

AIMS: To investigate the relationship between retinal nerve fibre layer thickness and peripheral neuropathy in patients with Type 2 diabetes, particularly in those who are at higher risk of foot ulceration. METHODS: Global and sectoral retinal nerve fibre layer thicknesses were measured at 3.45 mm diameter around the optic nerve head using optical coherence tomography (OCT). The level of neuropathy was assessed in 106 participants (82 with Type 2 diabetes and 24 healthy controls) using the 0-10 neuropathy disability score. Participants were stratified into four neuropathy groups: none (0-2), mild (3-5), moderate (6-8), and severe (9-10). A neuropathy disability score ≥ 6 was used to define those at higher risk of foot ulceration. Multivariable regression analysis was performed to assess the effect of neuropathy disability scores, age, disease duration and retinopathy on RNFL thickness. RESULTS: Inferior (but not global or other sectoral) retinal nerve fibre layer thinning was associated with higher neuropathy disability scores (P = 0.03). The retinal nerve fibre layer was significantly thinner for the group with neuropathy disability scores ≥ 6 in the inferior quadrant (P < 0.005). Age, duration of disease and retinopathy levels did not significantly influence retinal nerve fibre layer thickness. Control participants did not show any significant differences in thickness measurements from the group with diabetes and no neuropathy (P > 0.24 for global and all sectors). CONCLUSIONS: Inferior quadrant retinal nerve fibre layer thinning is associated with peripheral neuropathy in patients with Type 2 diabetes, and is more pronounced in those at higher risk of foot ulceration.

Glucose meters: evaluation of the new formulation measuring strips from Roche (Accu-Chek) and Abbott (MediSense).

BACKGROUND: Both Roche and Abbott have released new glucose meter strips. They supply the entire Australian hospital market. The present study compared the performance of the new strips utilizing various specimen types (capillary, venous lithium heparin whole blood, venous lithium heparin plasma and serum) and evaluated how well they comply with the International Standards Organization (ISO) 15197 criteria. METHODS: The study included imprecision, patient comparison and interference studies. Participants with and without diabetes were recruited to evaluate the performance of various specimen types against the Beckman DxC800 glucose method. The strips were tested for different interferences: galactose, maltose, lactose, Icodextrin, Intragam, paracetamol, sodium, ascorbic acid, variable strip storage temperature, haematocrit, haemolysis and lipaemia. RESULTS: The imprecision of the two strips was approximately 5% or less, except for the Abbott strip at very low values (1.4 mmol/L), approximately 7%. In total, 78% and 84%, respectively, of the results from the finger prick capillary specimens with the Roche (Accu-Chek Performa meter) and Abbott (Optium Xceed meter) strips, not 95% or greater as recommended by the ISO guideline, were within the recommended limits compared with reference plasma estimation on laboratory analysers. Galactose, ascorbic acid, haematocrit and sodium on the Roche and ascorbic acid and haematocrit on the Abbott strip continue to interfere to a variable degree with the glucose measurement. CONCLUSION: Analytically small differences exist between the glucose meter strips. The most significant analytical difference with the strips was at low glucose levels when compared with laboratory analyses and this may be of clinical importance. The impact of some of the interferences is variable between the two strips. Individuals, health-care professionals and health-care institutions should consider these data when selecting glucose meters for the management of people with diabetes mellitus.

The effect of acute hyperglycaemia on appetite and food intake in Type 1 diabetes mellitus.

AIMS: To determine the effects of acute hyperglycaemia on appetite and food intake in Type 1 diabetes mellitus. METHODS: Two separate studies, each involving eight adults with uncomplicated Type 1 diabetes, were performed: one in the fasted state (A) and the other after a nutrient preload (B). In both studies, perceptions of appetite (hunger and fullness) and food intake at a buffet meal were evaluated during euglycaemia (blood glucose, approximately 6 mmol/l) and hyperglycaemia (blood glucose, approximately 14 mmol/l). Both experiments were randomized and single-blind. In study A, appetite was assessed in the fasted state for 90 min before the buffet meal. In study B, a nutrient 'preload' of Ensure and milk containing 13C-octanoic acid was consumed 90 min before the meal. Gastric emptying of the preload was quantified with a radioisotopic breath test technique. RESULTS: There was no significant difference in plasma insulin concentrations between euglycaemia and hyperglycaemia in either study. In study A, there were no differences in hunger, fullness or energy intake between the two treatment days. In study B, subjects were slightly less hungry between the preload and buffet meal during hyperglycaemia than euglycaemia (P = 0.04), and tended to have slower gastric emptying during hyperglycaemia (emptying coefficient, 3.89 +/- 0.16 vs. 3.57 +/- 0.21; P = 0.052), but there was no difference in food intake between hyperglycaemia and euglycaemia. CONCLUSIONS: Acute hyperglycaemia suppresses hunger after a nutrient preload, but not in the fasted state, in patients with uncomplicated Type 1 diabetes. This effect is small and not associated with changes in food intake.

Photosystem II Regulation and Dynamics of the Chloroplast D1 Protein in Arabidopsis Leaves during Photosynthesis and Photoinhibition.

Arabidopsis thaliana leaves were examined in short-term (1 h) and long-term (10 h) irradiance experiments involving growth, saturating and excess light. Changes in photosynthetic and chlorophyll fluorescence parameters and in populations of functional photosystem II (PSII) centers were independently measured. Xanthophyll pigments, 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU)-binding sites, the amounts of D1 protein, and the rates of D1 protein synthesis were determined. These comprehensive studies revealed that under growth or light-saturating conditions, photosynthetic parameters remained largely unaltered. Photoprotection occurred at light saturation indicated by a dark-reversible increase in non-photochemical quenching accompanied by a 5-fold increase in antheraxanthin and zeaxanthin. No consistent change in the concentrations of functional PSII centers, DCMU-binding sites, or D1 protein pool size occurred. D1 protein synthesis was rapid. In excess irradiance, quantum yield of O2 evolution and the efficiency of PSII were reduced, associated with a 15- to 20-fold increase in antheraxanthin and zeaxanthin and a sustained increase in nonphotochemical quenching. A decrease in functional PSII center concentration occurred, followed by a decline in the concentration of D1 protein; the latter, however, was not matched by a decrease in DCMU-binding sites. In the most extreme treatments, DCMU-binding site concentration remained 2 times greater than the concentration of D1 protein recognized by antibodies. D1 protein synthesis rates remained unaltered at excess irradiances.

Background infusion with patient-controlled analgesia: effect on postoperative oxyhaemoglobin saturation and pain control.

The aim of this study was to determine whether the addition of a background infusion (BI) to patient-controlled analgesia (PCA) would lead to significantly improved pain control or poorer oxyhaemoglobin saturation (SpO2) after gynaecological surgery. Sixty-two patients were studied for 24 hours postoperatively; pain scores and morphine dose were recorded hourly, SpO2 was recorded every 10 seconds. Administration of the BI resulted in a significant increase in total morphine dose received although there was no difference in the severity of postoperative desaturation between the therapies. Despite the increased morphine dose pain scores also were similar in the two groups. Addition of a BI at 1 mg/hr did not confer any advantage over PCA alone and is not recommended when PCA is used in this patient group.

Empirical calibration of light blockage sensors.

The intent of this note is to describe in more detail the calibration process for these sensors with particular emphasis on the method of obtaining the best calibration curve from the raw data. A new method of assessing the accuracy of the calibration curve is also described.