+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

The older the better: are elderly study participants more non-representative? A cross-sectional analysis of clinical trial and observational study samples

, : The older the better: are elderly study participants more non-representative? A cross-sectional analysis of clinical trial and observational study samples. Bmj Open 2(6): -

Study participants can differ from the target population they are taken to represent. We sought to investigate whether older age magnifies such differences, examining age-trends, among study participants, in self-rated level of activity compared to others of the same age. Cross-sectional examination of the relation of participant age to reported 'relative activity' (ie, compared to others of the same age), a bidirectionally correlated proxy for relative vitality, in exemplars of randomised and observational studies. University of California, San Diego (UCSD) PARTICIPANTS: 2404 adults aged 40-79 including employees of UCSD, and their partners (San Diego Population Study, observational study). 1016 adults (aged 20-85) not on lipid medications and without known heart disease, diabetes, cancer or HIV (UCSD Statin Study, randomised trial). Self-rated activity relative to others' age, 5-point Likert Scale, was evaluated by age decade, and related via correlation and regression to a suite of health-relevant subjective and objective outcomes. Successively older participants reported successively greater activity relative to others of their age (greater departure from the norm for their age), p<0.001 in both studies. Relative activity significantly predicted (in regression adjusted for age) actual activity (times/week exercised), and numerous self-rated and objective health-predictors. These included general self-rated health, CES-D (depression score), sleep, tiredness, energy; body mass index, waist circumference, serum glucose, high-density lipoprotein-cholesterol, triglycerides and white cell count. Indeed, some health-predictor associations with age in participants were 'paradoxical,' consistent with greater apparent health in older age-for study participants. Study participants may not be representative of the population they are intended to reflect. Our results suggest that departures from representativeness may be amplified with increasing age. Consequently, the older the age, the greater the disparity may be between what is recommended based on 'evidence, ' and what is best for the patient. UCSD Statin # NCT00330980 (


PMID: 23242479

DOI: 10.1136/bmjopen-2012-000833

Other references

Anonymous, 1962: Horticultural Guide for The Netherlands, 1963. Articles in the crop sections in this edition include the following: Vegetables: the use of extra CO2 in lettuce growing; stages of ripening and diseases of tomatoes (with coloured illustrations); early forcing of chicory. Fruit: the culture of th...

Jeromin, Alice, 2001: Nocardiosis- easy to miss, difficult to treat. DVM 32(7): 8S

Hawley, P.; Nelson, J.S.; Fearon, K.L.; Zon, G.; Gibson, I., 1999: Comparison of binding of N3' fwdarw P5' phosphoramidate and phosphorothioate oligonucleotides to cell surface proteins of cultured cells. The binding of uniformly modified N3' fwdarw P5' phosphoramidate and stereorandom and stereopure phosphorothioate oligonucleotides (ODN) to cell surface proteins was studied, using both a fibroblast and an epithelial cell line, to assess...

Bravo Ruiz, G.; D.P.etro, A.; Roncero, M.Isabel.G., 2015: Combined action of the major secreted exo- and endopolygalacturonases is required for full virulence of Fusarium oxysporum. The genome of the tomato pathogen Fusarium oxysporum f. sp. lycopersici encodes eight different polygalacturonases (PGs): four endoPGs and four exoPGs. Quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) revealed that e...

Winkelmann, R.K.; Mulder, D.W.; Lambert, E.H.; Howard, F.M.; Diessner, G.R., 1968: Course of dermatomyositis-polymyositis: comparison of untreated and cortisone-treated patients. Mayo Clinic Proceedings 43(8): 545-556

Verdejo Ortés, J.; Polo Rodríguez, R.M.; Fenoy Rodríguez, P.A.; González Lahoz, J.M., 1986: Erythema nodosum associated with Salmonella enteritidis gastroenteritis. Revista Clinica Espanola 178(3): 151-151

Bandrin S.V.; Rabinovich P.M.; Stepanov A.I., 1983: 3 linkage groups of genes involved in riboflavin biosynthesis in escherichia coli. Using transposon Tn5 inactivation technology, a collection of E. coli mutants defective in riboflavin biosynthesis was obtained. All mutations were distributed within 3 linkage groups. With the help of P1-transduction mapping, group I mutations (r...

Oyer, Calvin E., 1992: Juxtagonadal mesonephric glomeruli in fetuses of 11 to 21 weeks of gestation. Mesonephric glomeruli and tubules were found in the juxtagonadal region in 11 fetuses ranging in age from 11 to 21 postmenstrual weeks. Although mesonephric excretory function into the fourth month of gestation has been postulated, mesonephric glo...

Mazza S.; Azzoni A.; Laudisio A., 1987: Epilepsy individual consequences of a diagnosis. The authors, starting from their customary point of view which gives preference to the approach to the patient in his globality as a person, deal with the problem of the consequence connected with a first diagnosis of epilepsy. The topic is discus...

Athanasiou, T.; Casula, R.; Charitou, A.; Kavia, S.; Skipworth, J.; Stanbridge, R.De.L.; Glenville, B., 2003: How I do it: a new method of myocardial revascularization with use of the radial loop technique. We report a technique that allows total arterial myocardial revascularization of the left ventricle by the use of the radial artery as a composite graft. The technique includes anastomosis of the distal end of the radial artery to its more proxima...