Are cholesterol lowering drugs useful? Do they increase life expectancy? Do third generation oral contraceptives increase the risk of venous thromboembolism? Is there a worldwide decline in semen quality over the last 50 years? Do vitamin supplements improve your child's IQ? Does homeopathy work better than placebo? These questions illustrate some statistical problems and some bias encountered during clinical studies, which can lead to erroneous results. Type I and II errors, surveillance, prescription or publication bias as well as the healthy user effect are described.
CONTEXT: Although acupuncture and homeopathy both have a theoretical background that refers to immaterial forces difficult to verify, they are nevertheless used and accepted as effective treatments by many individuals. OBJECTIVE: We intended to investigate whether and how users of acupuncture and homeopathy differ with respect to sociodemographic data, adaptive coping strategies, and attitudes toward complementary and alternative medicine (CAM).
BACKGROUND: Estimating a realistic effect size is an important issue in the planning of clinical studies of complementary and alternative medicine therapies. When a minimally important difference is not available, researchers may estimate effect size using the published literature. This evidence-based effect size estimation may be used to produce a range of empirically-informed effect size and consequent sample size estimates. We provide an illustration of deriving plausible effect size ranges for a study of acupuncture in the relief of post-chemotherapy fatigue in breast cancer patients.
Acupuncture in Medicine: Journal of the British Medical Acupuncture Society
BACKGROUND: In trials, 'therapist intensive' complex interventions are typically delivered over time, during which a relationship between the practitioner and participant may develop. Such relationships are sometimes criticised as obscuring any 'true' treatment effect. Limiting interactions is one strategy that might be used to try to control for the effect of a therapeutic relationship.
BACKGROUND: In a recent individual patient data meta-analysis, acupuncture was found to be superior to both sham and non-sham controls in patients with chronic pain. In this paper we identify variations in types of sham and non-sham controls used and analyze their impact on the effect size of acupuncture. METHODS: Based on literature searches of acupuncture trials involving patients with headache and migraine, osteoarthritis, and back, neck and shoulder pain, 29 trials met inclusion criteria, 20 involving sham controls (n = 5,230) and 18 non-sham controls (n = 14,597).
OBJECTIVE: Acupuncture has become popular and widely practiced in many countries around the world. Despite the large amount of acupuncture-related literature that has been published, broader trends in the prevalence and scope of acupuncture research remain underexplored. The current study quantitatively analyzes trends in acupuncture research publications in the past 20 years. METHODS: A bibliometric approach was used to search PubMed for all acupuncture-related research articles including clinical and animal studies.
The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences
BACKGROUND: Families of centenarians have high levels of plasma high-density lipoprotein (HDL) cholesterol, which may have neurological as well as cardiovascular protective effects during aging. Because plasma HDL level declines progressively with aging, we examined whether centenarians with higher plasma HDL levels have better cognitive function.
The purpose of this study is to test the prediction of the evolutionary theory of aging that human longevity comes with the cost of impaired reproductive success (higher infertility rates). Our validation study is based on the analysis of particularly reliable genealogical records for European aristocratic families using a logistic regression model with childlessness as a dependent (outcome) variable, and woman's life span, year of birth, age at marriage, husband's age at marriage, and husband's life span as independent (predictor) variables.
The Journal of Clinical Endocrinology and Metabolism
CONTEXT: Exceptional longevity is associated with raised serum TSH. OBJECTIVE: The aim of this study was to examine whether offspring of people with exceptional longevity have elevated serum TSH and whether specific single nucleotide polymorphisms (SNPs) in the TSH-B gene and TSH receptor (TSHR) gene are associated with this phenotype. DESIGN/SETTING/PATIENTS: We measured serum TSH and free T(4) in Ashkenazi Jewish centenarians (n = 232; median age, 97 yr), their offspring (n = 366; median age, 69 yr), and age-matched controls without familial longevity (n = 163; median age, 70 yr).
Mortality hazard and length of time until death are widely used as health outcome measures and are themselves of fundamental demographic interest. Considerable research has asked whether labor force retirement reduces subsequent health and its mortality measures. Previous studies have reported positive, negative, and null effects of retirement on subsequent longevity and mortality hazard, but inconsistent findings are difficult to resolve because (1) nearly all data confound retirement with unemployment of older workers, and often, (2) endogeneity bias is rarely addressed analytically.