Cost-effectiveness of varying degrees and models of therapist-assisted transdiagnostic internet-delivered cognitive behaviour therapy: Evidence from a randomized controlled trial.

In routine care, Internet-delivered Cognitive Behaviour Therapy (ICBT) is often delivered with therapist support via emails/phone calls, but the cost-effectiveness of varying amounts of therapist support or having therapists specialized in ICBT is not known. This study compared the cost-effectiveness of specialized therapists providing ICBT support once-weekly (1WS) versus providing support once-weekly supplemented with a one-business-day response to patient emails (1W/1BD-S). We further compared the cost-effectiveness of 1W support offered by therapists employed in a specialized clinic (1WS) versus community clinics where therapists primarily deliver face-to-face therapy (1WC). Patients were randomly allocated to groups: 1WS group (n = 216), 1W/1BD-S group (n = 233), and 1WC group (n = 226). At baseline, 12, 24 and 52-week follow-up, patients completed the Treatment Inventory of Costs in Patients with Psychiatric Disorders questionnaire (TiC-P) adapted for use in Canada to assess healthcare use and productivity losses. Additionally, to assess Quality Adjusted Life Years (QALYs) gained, patients completed the EQ-5D-5L at the same time periods. We quantified uncertainties by one-way and probabilistic sensitivity analysis and reported Incremental cost-effectiveness ratios (ICER), cost-effectiveness planes and acceptability curves. Cost-effectiveness over 52 weeks was CAD 3072/QALY for 1WC, CAD 3244/QALY for 1W/1BD-S, and CAD 3528/QALY for 1WS. Our model suggests that 1WS is the best strategy since the incremental cost per QALY is below the $50,000 threshold (ICER is CAD 42,328/QALY compared to the next most effective, 1WC). 1W/1BD-S is dominated by the other strategies. The cost-effectiveness acceptability curves suggest that the 1WS group has a higher probability for cost-effectiveness (38 %) than 1W/1BD-S (30 %) and 1WC (32 %) when the willingness to pay is $50,000 per QALY. These results have important implications for health policymakers deciding on delivery of ICBT for the treatment of anxiety and/depressive disorders.

Biodegradation of oil in uplifted basins prevented by deep-burial sterilization.

Biodegradation of crude oil by bacterial activity--which has occurred in the majority of the Earth's oil reserves--is known to reduce greatly the quality of petroleum in reservoirs. For economically successful prospecting for oil, it is therefore important to understand the processes and conditions in geological formations that lead to oil biodegradation. Although recent studies speculate that bacterial activity can potentially occur up to temperatures as high as 150 degrees C (refs 3, 4), it is generally accepted that effective petroleum biodegradation over geological timescales generally occurs in reservoirs with temperatures below 80 degrees C (ref. 2). This appears, however, to be at odds with the observation that non-degraded oils can still be found in reservoirs below this temperature. Here we compile data regarding the extent of oil biodegradation in several oil reservoirs, and find that the extensive occurrence of non-biodegraded oil in shallow, cool basins is restricted to those that have been uplifted from deeper, hotter regions of the Earth. We suggest that these petroleum reservoirs were sterilized by heating to a temperature around 80-90 degrees C during deep burial, inactivating hydrocarbon-degrading organisms that occur in the deep biosphere. Even when such reservoirs are subsequently uplifted to much cooler regions and filled with oil, degradation does not occur, implying that the sterilized sediments are not recolonized by hydrocarbon-degrading bacteria.

A first step incorporating smoking education into a Brazilian medical school curriculum: results of a survey to assess the cigarette smoking knowledge, attitudes, behaviour, and clinical practices of medical students.

Smoking-related illnesses are the leading causes of morbidity and mortality in Brazil. Despite a smoking prevalence of approximately 40%, there is limited national effort to reduce tobacco use in Brazil by means of public education and training of health care professionals to promote smoking education. In particular, the need for information about tobacco warrants increased emphasis in undergraduate medical education. An educational program on nicotine addiction during medical school could facilitate the incorporation of smoking cessation interventions into routine medical practice. As a preliminary step toward implementing a tobacco education and intervention program, this study was designed to assess knowledge and attitudes about smoking among Brazilian medical students. Five hundred thirteen (N = 513) medical students from the Federal University of Rio Grande do Sul, the southernmost state of Brazil, completed a self-reported questionnaire during the 1995-1996 academic school year. Most students recognize the adverse health effects of smoking and the importance of their professional role in promoting smoking cessation. In contradiction, however, few medical students currently provide their patients who smoke with even minimal intervention. This discrepancy supports the idea that training in nicotine addiction and smoking cessation techniques will help medical students to develop the skills and confidence needed to successfully intervene with their current and future patients.