Does Patient Health Behaviour respond to Doctor Effort?

Incentive pay systems have been introduced in public sectors such as education and health care. In these sectors the output (education or health respectively) depends on the actions of different agents and it is unclear what the effects of such incentive systems are on the behaviour of untargeted agents. In this study we focus on patient health, modelled as a joint product of patient effort (through lifestyle and behaviour) and doctor effort (through diagnosis and treatment). Patient response to doctor effort is shown to be a priori ambiguous and depends on the degree of complementarity or substitution between doctor and patient effort. We build an empirical model to estimate the effect of doctors’ treatment effort on patient behaviour. To address the endogeneity of doctor effort we exploit a change in payments to doctors in the U.K. that led to incentive changes that varied by practice, depending on their prior performance levels. We use panel data on the physical activity, drinking and smoking behaviours of over 2,000 cardiovascular disease patients aged over 50 in England and link these data to their primary care practice performance data. Our results indicate that primary care practices increased the proportion of patients with controlled disease from 76% to 83% in response to the payment change. Patients responded by reducing the frequency of drinking alcohol and their cigarette consumption, suggesting that patient efforts are complements to doctor effort. Understanding such complementarities has implications for assessing the design and effectiveness of pay-for-performance schemes which encourage higher doctor effort

Does Patient Health Behaviour respond to Doctor’s Effort?

Incentive pay systems have been introduced in public sectors such as education and healthcare. In these organisations where the outcome (health or education) is a joint product between different agents, it is unclear what the effects of these incentives are onto the behaviour of untargeted agents. We focus on patient health as a joint product of patient effort, through lifestyle and behaviour, and doctor effort, through diagnosis and treatment. Patient response to doctor effort is a priori ambiguous and depends on the degree of complementarity or substitution between doctor and patient effort. We use data on the physical activity, drinking and smoking behaviours of over 2,000 patients aged over 50 with cardiovascular diseases in England. Through a new data linkage and an instrumental variable approach, we test whether changes in doctors’ treatment efforts triggered by changes in their payment system between 2004 and 2006 had an impact on patient behaviour. Doctors working in primary care practices increased the proportion of patients with controlled disease from 76% to 83% in response to the payment change. Patients responded by reducing the frequency of drinking alcohol and their cigarette consumption. This suggests that patient efforts are complements to doctor effort. The results have implications for the effectiveness of pay-for-performance schemes which encourage higher doctor effort, and the design of such incentive schemes

Thick tori around AGN: the case for extended tori and consequences for their X-ray and IR emission

Two families of models of dusty tori in AGNs (moderately thick and extended versus very thick and compact) are tested against available observations. The confrontation suggests that the former class better explains the IR broad-band spectra of both broad and narrow line AGNs, the anisotropy of the emission deduced by comparing IR properties of Seyfert 1 and 2 nuclei, the results of IR spectroscopy and those of high spatial resolution observations. There is however clear evidence for a broad distribution of optical depths. We also examine the relationship between IR and X-ray emission. The data support a view in which the matter responsible for the X-ray absorption is mostly dust free, lying inside the dust sublimation radius. The consequences of these results for the hard X-ray background as well as IR counts and background are discussed.Comment: 33 pages, 9 Postscript figures, to appear in ApJ, September 199

An X-ray polarimeter for hard X-ray optics

Development of multi-layer optics makes feasible the use of X-ray telescope at energy up to 60-80 keV: in this paper we discuss the extension of photoelectric polarimeter based on Micro Pattern Gas Chamber to high energy X-rays. We calculated the sensitivity with Neon and Argon based mixtures at high pressure with thick absorption gap: placing the MPGC at focus of a next generation multi-layer optics, galatic and extragalactic X-ray polarimetry can be done up till 30 keV.Comment: 12 pages, 7 figure

Lower mitochondrial energy production of the thigh muscles in patients with low-normal ankle-brachial index

Background--Lower muscle mitochondrial energy production may contribute to impaired walking endurance in patients with peripheral arterial disease. A borderline ankle-brachial index (ABI) of 0.91 to 1.10 is associated with poorer walking endurance compared with higher ABI. We hypothesized that in the absence of peripheral arterial disease, lower ABI is associated with lower mitochondrial energy production. Methods and Results--We examined 363 men and women participating in the Baltimore Longitudinal Study of Aging with an ABI between 0.90 and 1.40. Muscle mitochondrial energy production was assessed by post-exercise phosphocreatine recovery rate constant (kPCr) measured by phosphorus magnetic resonance spectroscopy of the left thigh. A lower post-exercise phosphocreatine recovery rate constant reflects decreased mitochondria energy production.The mean age of the participants was 71\uc2\ub112 years. A total of 18.4% had diabetes mellitus and 4% were current and 40% were former smokers. Compared with participants with an ABI of 1.11 to 1.40, those with an ABI of 0.90 to 1.10 had significantly lower post-exercise phosphocreatine recovery rate constant (19.3 versus 20.8 ms-1, P=0.015). This difference remained significant after adjusting for age, sex, race, smoking status, diabetes mellitus, body mass index, and cholesterol levels (P=0.028). Similarly, post-exercise phosphocreatine recovery rate constant was linearly associated with ABI as a continuous variable, both in the ABI ranges of 0.90 to 1.40 (standardized coefficient=0.15, P=0.003) and 1.1 to 1.4 (standardized coefficient=0.12, P=0.0405). Conclusions--An ABI of 0.90 to 1.10 is associated with lower mitochondrial energy production compared with an ABI of 1.11 to 1.40. These data demonstrate adverse associations of lower ABI values with impaired mitochondrial activity even within the range of a clinically accepted definition of a normal ABI. Further study is needed to determine whether interventions in persons with ABIs of 0.90 to 1.10 can prevent subsequent functional decline