38 research outputs found
Welfare Effects of Pharmaceutical Informative Advertising
No full textPharmaceutical markets are characterized by a high degree of innovation, complexity and uncertainty, especially markets of idiosyncratic symptomatolgy and response to treatment such as the antidepressant market. It may, therefore, be unreasonable to assume that consumers are aware of all antidepressants for sale at the time of purchase, as is the case in traditional models of consumer choice. Such an assumption will bias demand curves towards being more elastic and the evaluation of consumer welfare downwards. This paper, therefore, aims at analyzing and evaluating the effects of promotions by pharmaceutical firms on patient welfare taking into account the interaction of multiple agents (patients, physicians, insurance companies and pharmaceutical companies) in the decision process. I present an empirical discrete-choice model of limited information, where advertising influences the set of drugs from which a purchase choice is made. The estimation technique incorporates both macro- and micro-level data. Estimation results indicate that pharmaceutical firms use advertising media to target high-income households and households with more comprehensive prescription drug insurance schemes through their physicians or directly. Model comparison shows that limited information leads to less elastic demand curves and larger estimates of patient welfare due to pharmaceutical innovation that exacerbate the moral hazard issue that coexists with insurance coverage.Advertising, Health, Information, Moral Hazard, Pharmaceuticals, Welfare
Nonparametric Bayesian modelling of longitudinally integrated covariance functions on spheres
No full textTaking into account axial symmetry in the covariance function of a Gaussian random field is essential when the purpose is modelling data defined over a large portion of the sphere representing our planet. Axially symmetric covariance functions admit a convoluted spectral representation that makes modelling and inference difficult. This motivates the interest in devising alternative strategies to attain axial symmetry, an appealing option being longitudinal integration of isotropic random fields on the sphere. This paper provides a comprehensive theoretical framework to model longitudinal integration on spheres through a nonparametric Bayesian approach. Longitudinally integrated covariances are treated as random objects, where the randomness is implied by the randomised spectrum associated with the covariance function. After investigating the topological support induced by our construction, we give the posterior distribution a thorough inspection. A Bayesian nonparametric model for the analysis of data defined on the sphere is described and implemented, its performance investigated by means of the analysis of both simulated and real data sets
Adaptive estimation of the -norm of a probability density and related topics II. Upper bounds via the oracle approach
No full textThis is the second part of the research project initiated in Cleanthous et al
(2024). We deal with the problem of the adaptive estimation of the
-norm of a probability density on , , from
independent observations. The unknown density is assumed to be uniformly
bounded by unknown constant and to belong to the union of balls in the
isotropic/anisotropic Nikolskii's spaces. In Cleanthous et al (2024) we have
proved that the optimally adaptive estimators do no exist in the considered
problem and provided with several lower bounds for the adaptive risk. In this
part we show that these bounds are tight and present the adaptive estimator
which is obtained by a data-driven selection from a family of kernel-based
estimators. The proposed estimation procedure as well as the computation of its
risk are heavily based on new concentration inequalities for decoupled
-statistics of order two established in Section 4. It is also worth noting
that all our results are derived from the unique oracle inequality which may be
of independent interest
Increased thiamine intake may be required to maintain thiamine status during weight loss in patients with type 2 diabetes
No full textDuring weight loss, erythrocyte thiamine pyrophosphate (TPP) decreased (221 ± 52 to 195 ± 39 nmol/L, P < 0.05) on a diet with adequate thiamine (1.1 mg/day) but was unchanged (217 ± 55 vs 218 ± 52 nmol/L, NS) on a high thiamine diet (2.8 mg/day). Attention to thiamine status may be required in patients with diabetes after weight loss.Jennifer B. Keogh, X. Cleanthous, T.P. Wycherley, G.D. Brinkworth, M. Noakes, Peter M. Clifto
Timing of protein ingestion relative to resistance exercise training does not influence body composition, energy expenditure, glycaemic control or cardiometabolic risk factors in a hypocaloric, high protein diet in patients with type 2 diabetes
No full textAim: To investigate timing of protein ingestion relative to resistance exercise training (RT) on body composition, cardiometabolic risk factors, glycaemic control and resting energy expenditure (REE) during weight loss on a high-protein (HP) diet in overweight and obese patients with type 2 diabetes (T2DM).
Methods: Thirty-four men/women with T2DM (age 57 ± 7 years and body mass index 34.9 ± 4.2 kg m−2) were randomly assigned to the ingestion of a HP meal (860 kJ, 21 g protein, 0.7 g fat, 29.6 g carbohydrate) either immediately prior to RT or at least 2 h following RT. All participants followed a 16-week, energy-restricted (6-7 MJ day−1), HP diet (carbohydrate : protein : fat 43 : 33 : 22) and participated in supervised RT (3 day week−1). Outcomes were assessed pre- and postintervention at 16 weeks.
Results: There was an overall reduction in bodyweight (−11.9 ± 6.1 kg), fat mass (−10.0 ± 4.4 kg), fat-free mass (−1.9 ± 3.1 kg), waist circumference (−12.1 ± 5.3 cm), REE (−742 ± 624 kJ day−1), glucose (−1.9 ± 1.7 mmol l−1), insulin (−6.1 ± 6.7 mU l−1) and glycosylated haemoglobin (−1.1 ± 0.1%), p ≤ 0.01 time for all variables, with no difference between groups (p ≥ 0.41 group effect). Strength improved and cardiometabolic risk factors were reduced similarly in both groups; single repetition maximum chest press 11.0 ± 8.7 kg, single repetition maximum lat pull down 9.9 ± 6.0 kg, total cholesterol −0.6 ± 0.5 mmol l−1, high-density lipoprotein cholesterol −0.1 ± 0.2 mmol l−1, low-density lipoprotein cholesterol −0.3 ± 0.5 mmol l−1, triglycerides −0.6 ± 0.7 mmol l−1, blood pressure (systolic/diastolic) −13 ± 10/−7 ± 7 mmHg (p ≤ 0.04 time effect, p ≥ 0.24 group effect).
Conclusion: A HP, energy-restricted diet with RT was effective in improving glycaemic control, body composition, strength and cardiometabolic risk factors in overweight/obese patients with T2DM irrespective of altering the timing of protein ingestion relative to RT.T. P. Wycherley, M. Noakes, P. M. Clifton, X. Cleanthous, J. B. Keogh & G. D. Brinkwort
Adaptive estimation of -norm of a probability density and related topics I. Lower bounds
No full textWe deal with the problem of the adaptive estimation of the
-norm of a probability density on , , from
independent observations. The unknown density is assumed to be uniformly
bounded and to belong to the union of balls in the isotropic/anisotropic
Nikolskii's spaces. We will show that the optimally adaptive estimators over
the collection of considered functional classes do no exist. Also, in the
framework of an abstract density model we present several generic lower bounds
related to the adaptive estimation of an arbitrary functional of a probability
density. These results having independent interest have no analogue in the
existing literature. In the companion paper Cleanthous et al (2024) we prove
that established lower bounds are tight and provide with explicit construction
of adaptive estimators of -norm of the density
A pilot comprehensive lifestyle intervention program (CLIP) - Comparison with qualitative lifestyle advice and simvastatin on cardiovascular risk factors in overweight hypercholesterolaemic individuals
No full textData source: Figures & tables, https://doi.org/10.1016/j.numecd.2009.09.002Background and Aims: Escalating costs of pharmaceuticals for cardiovascular management highlight the need to develop effective lifestyle intervention programs to reduce reliance on these agents. The aim of this pilot study was to evaluate the efficacy of a Comprehensive Lifestyle Intervention Program (CLIP) compared with qualitative lifestyle advice (L) and Simvastatin plus qualitative lifestyle (S + L) on cardiovascular risk factors.
Methods and Results: Sixty-five overweight adults with hypercholesterolemia were randomised to either L (qualitative advice on diet, exercise), S + L (20 mg/day Simvastatin plus L) or CLIP (6500 kJ structured menu plan: conventional and functional foods contributing 0.05, all). Blood pressure changes were not different between groups.
Conclusions: The structured CLIP program was more effective than qualitative lifestyle advice in improving weight, waist circumference and LDL-cholesterol without adverse effects on plasma carotenoids over a 6 week period. This program may therefore assist in comprehensive risk factor management, although the sustainability of these benefits needs confirmation.X. Cleanthous, M. Noakes, G.D. Brinkworth, J.B. Keogh, G. Williams, P.M. Clifto
Long-term follow-up using a higher target range for lamotrigine monitoring
No full textThe aims of the study were (1) to review the clinical application of the higher target plasma lamotrigine (LTG) concentration of 3-14 mg/L previously proposed by our therapeutic drug monitoring (TDM) laboratory following our initial study 7 years earlier, and (2) to survey clinical application of LTG assays by experienced neurologists (n = 11) who frequently use LTG. There was a 2.9-fold increase in LTG assay requests received by our laboratory from 1996 to 2003. By comparison, data for the number of LTG prescriptions filled throughout Australia were limited to the 4 years from 1997 to 2000, where a 1.7-fold increase was seen. LTG assay requests increased 1.5-fold in this same 4-year period (r2 = 0.97), indicating that the growth in assay requests paralleled the growth in prescriptions. The distribution of LTG concentrations measured in 2003 was compared with those for 1996 and 1997. This indicated there was a significantly increased (P < 0.01) clinical usage of the higher LTG target range. This result was reinforced by questionnaire responses. Respondents (100% of those surveyed), (1) considered the target LTG concentration (3-14 mg/L) to be one of the primary parameters applied in individualizing LTG dosage regimens, (2) were using target concentrations above 7 mg/L in 75% of patients, and (3) reported dose-limiting toxicities in some (but not all) patients typically at concentrations above, or well above, 13 mg/L. In conclusion, the growth in LTG assay requests received by our laboratory paralleled prescribing of this drug. The clinical use of the higher LTG target concentration range was increased during the 7 years since its introduction, indicating clinical acceptance and therapeutic benefit as well as the absence of long-term adverse effects associated with higher plasma LTG concentrations.Morris, Raymond G.; Lee, Michelle Y. Y.; Cleanthous, Xenia; Black, Andrew
A high-protein diet with resistance exercise training improves weight loss and body composition in overweight and obese patients with Type 2 diabetes
No full textOBJECTIVE: To evaluate the effects of two low-fat hypocaloric diets differing in the carbohydrate-to-protein ratio, with and without resistance exercise training (RT), on weight loss, body composition, and cardiovascular disease (CVD) risk outcomes in overweight/obese patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: A total of 83 men and women with type 2 diabetes (aged 56.1 ± 7.5 years, BMI 35.4 ± 4.6 kg/m2) were randomly assigned to an isocaloric, energy-restricted diet (female subjects 6 MJ/day, male subjects 7 MJ/day) of either standard carbohydrate (CON; carbohydrate:protein:fat 53:19:26) or high protein (HP; 43:33:22), with or without supervised RT (3 days/week) for 16 weeks. Body weight and composition, waist circumference (WC), and cardiometabolic risk markers were assessed. RESULTS: Fifty-nine participants completed the study. There was a significant group effect (P ≤ 0.04) for body weight, fat mass, and WC with the greatest reductions occuring in HP+RT (weight [CON: −8.6 ± 4.6 kg, HP: −9.0 ± 4.8 kg, CON+RT: −10.5 ± 5.1 kg, HP+RT: −13.8 ± 6.0 kg], fat mass [CON: −6.4 ± 3.4 kg, HP: −6.7 ± 4.0 kg, CON+RT: −7.9 ± 3.7 kg, HP+RT: −11.1 ± 3.7 kg], and WC [CON: −8.2 ± 4.6 cm, HP: −8.9 ± 3.9 cm, CON+RT: −11.3 ± 4.6 cm, HP+RT: −13.7 ± 4.6 cm]). There was an overall reduction (P < 0.001) in fat-free mass (−2.0 ± 2.3 kg), blood pressure (−15/8 ± 10/6 mmHg), glucose (−2.1 ± 2.2 mmol/l), insulin (−4.7 ± 5.4 mU/l), A1C (−1.25 ± 0.94%), triglycerides (−0.47 ± 0.81 mmol/l), total cholesterol (−0.67 ± 0.69 mmol/l), and LDL cholesterol (−0.37 ± 0.53 mmol/l), with no difference between groups (P ≥ 0.17). CONCLUSIONS: An energy-restricted HP diet combined with RT achieved greater weight loss and more favorable changes in body composition. All treatments had similar improvements in glycemic control and CVD risk markers.Thomas P. Wycherley, Manny Noakes, Peter M. Clifton, Xenia Cleanthous, Jennifer B. Keogh and Grant D. Brinkwort
