Sensitivity analysis in cost-effectiveness studies: from guidelines to practice

Cost-effectiveness analysis (CEA) is one of the main tools of economic evaluation. Every CEA is based on a number of assumptions, some of which may not be accurate, introducing uncertainty. Sensitivity analysis (SA) formalizes ways to measure and evaluate this uncertainty. Specific sources of uncertainty in CEA have been noted by various researchers. In this work, we consolidate across all sources of uncertainty, discuss the imbalanced attention to SA across different sources, and discuss criteria for conducting and reporting SA to help bridge the gap between guidelines and practice. Guidelines on how to perform SA have been published for many years in response to requests for greater standardization among researchers. Decision makers tasked with reviewing new health technologies also seem to appreciate the additional information conveyed by a robust SA, including the attention to important patient subgroups. Yet, past reviews have shown that there is a substantial gap between the guidelines' suggestions and the quality of SA in the field. Past reviews have also focused on one or two but not all three sources of uncertainty. The objective of our work is to comprehensively review all different sources of uncertainty and provide a concise set of criteria for conducting and presenting SA, stratified by common modelling approaches, including decision analysis and regression models. We first provide an overview of the three sources of uncertainty in a CEA (parameter, structural and methodological), including patient heterogeneity. We then present results from a literature review of the conduct and reporting of SA based on 406 CEA articles published between 2000 and mid-2009. We find that a minority of papers addressed at least two of the three sources of uncertainty, with no change over time. On the other hand, the use of some sophisticated techniques, such as probabilistic SA, has surged over the past 10 years. Lastly, we identify criteria for reporting uncertainty-robust SA and also discuss how to conduct SA and how to improve the reporting of SA for decision makers. We recommend that researchers take a more comprehensive view of uncertainty when planning SA for an economic evaluation.     

伊莫州奥韦里地区技术工人眼部疾病患病率及类型调查分析

目的：评估技术工人眼部疾病患病率及模式,向有关部门建议施行必要政策以保护技术工人眼部健康。

方法：描述性横断面研究。采用比例抽样技术和随机简单抽样法进行样本选择。

结果：技术工人中退行性结膜疾病并伴有睑裂黄斑以30.1%患病率高居第一。汽车工中结膜性疾病、角膜混浊、过敏性结膜炎发病率较高。表体异物是与工伤有关的最常见的损伤,而13.6%的工人由此发展为白内障。

结论：政府应该施行可以保护技术工人眼部健康的政策,以减少睑裂黄斑及其它几种眼部疾病的发生。     

Diabetes: knowledge,psychosocial impact,and attitude of patients

The scourge of diabetes has been increasing worldwide with a tendency to double, from 176 to 370 million people by 2030 according to WHO prediction. In Nigeria, only 20 % of the 3.2 million estimated to have diabetes are aware of it. Among those already diagnosed, about 50 % have poor glycaemic control attributable to poor diabetes self-management despite effective medication. Diabetes self-management in addition to medical therapy, lifestyle modification and education are key to the management of diabetes. This study aims to determine the knowledge, psychosocial impact and attitude of people with diabetes to diabetes with a view to make recommendations for a more encompassing patient-based management of diabetes. A cross-sectional study using a structured questionnaire in the endocrinology clinic of the Federal Medical Centre, Owerri, interviewed 104 consecutive newly diagnosed patients with diabetes who willingly consented to the study. One hundred and four patients with an equal male to female ratio were interviewed. The 41–60-year (78.8 %) age group and traders (66.3 %) constituted the greatest number. Majority (58.7 %) heard of diabetes prior to their diagnosis, but many (41.3 %) did not. This knowledge was significantly associated with occupation (0.022). Many (84.6 %) were willing to disclose diagnosis to family and friends as well as join a support group (61.5 %). But, the major reason for this inclination was wrong. Many never heard of diabetes prior to their diagnosis. In spite of being aware, a diagnosis of diabetes is associated with different emotional responses and attitudes including willingness to disclose their diagnosis and get support. Appropriate treatment based on current medical knowledge, self-management education and development of diabetic support groups is recommended.

     

Chemotherapy treatment and survival in older women with estrogen receptor-negative metastatic breast cancer: a population-based analysis

To investigate the survival benefit associated with chemotherapy receipt in older women with estrogen receptor–negative (ER–) Stage IV breast cancer. DESIGN: Observational, retrospective cohort study using Cox proportional hazards regression to determine effect of chemotherapy on hazard of all‐cause mortality. The two samples were an overall sample (n=1,519) and a propensity score–matched sample (n=580) to control for selection to treatment receipt. Hazard ratios (HRs) and 95% confidence intervals (CIs) were obtained for regression models. SETTING: U.S. women within the National Cancer Institute Surveillance, Epidemiology and End Results cancer registries (SEER) linked to Medicare enrollment and claims database. PARTICIPANTS: Female Medicare beneficiaries aged 66 and older with Stage IV ER– breast cancer diagnosed between 1999 and 2005. MEASUREMENTS: Outcome measure was all‐cause death during the follow‐up period. Survival was measured as time from breast cancer diagnosis until death or last follow‐up date. Information on receipt of chemotherapy, defined as chemotherapy received within 6 months after diagnosis, was obtained from linked Medicare claims. RESULTS: One thousand five hundred nineteen ER– women diagnosed with metastatic breast cancer were identified; 494 (33%) received chemotherapy. Chemotherapy was associated with a statistically significant survival benefit (HR=0.61, 95% CI=0.54–0.70). Age did not modify the survival benefit of chemotherapy. CONCLUSION: Chemotherapy received within 6 months after diagnosis was associated with a 39% lower hazard of death within the time period for the study. These findings reflect chemotherapy use outside of the clinical trial setting and have important clinical and policy implications for the study of treatments in older women with advanced ER– breast cancer.