The use of individual cut points from treadmill walking to assess free-living moderate to vigorous physical activity in obese subjects by accelerometry: is it useful?

abstract：BACKGROUND:The construction of prediction intervals (PIs) for future body mass index (BMI) values of individual children based on a recent German birth cohort study with n = 2007 children is problematic for standard parametric approaches, as the BMI distribution in childhood is typically skewed depending on age. METHO...

journal_title：BMC medical research methodology

authors： Mayr A,Hothorn T,Fenske N

更新日期：2012-01-25 00:00:00

abstract：BACKGROUND:Navigating the world of qualitative thematic analysis can be challenging. This is compounded by the fact that detailed descriptions of methods are often omitted from qualitative discussions. While qualitative research methodologies are now mature, there often remains a lack of fine detail in their descriptio...

journal_title：BMC medical research methodology

authors： Roberts K,Dowell A,Nie JB

更新日期：2019-03-28 00:00:00

abstract：BACKGROUND:Due to limited duration of follow up in clinical trials of cancer treatments, estimates of lifetime survival benefits are typically derived using statistical extrapolation methods. To justify the method used, a range of approaches have been proposed including statistical goodness-of-fit tests and comparing e...

journal_title：BMC medical research methodology

authors： Bullement A,Willis A,Amin A,Schlichting M,Hatswell AJ,Bharmal M

更新日期：2020-05-06 00:00:00

abstract：BACKGROUND:We demonstrate an application of Group-Based Trajectory Modeling (GBTM) based on the beta distribution. It is offered as an alternative to the normal distribution for modeling continuous longitudinal data that are poorly fit by the normal distribution even with censoring. The primary advantage of the beta di...

journal_title：BMC medical research methodology

authors： Elmer J,Jones BL,Nagin DS

更新日期：2018-11-26 00:00:00

abstract：BACKGROUND:To determine if the search technique that is used to sample randomized controlled trial (RCT) manuscripts from a field of medical science can influence the measurement of the change in quality over time in that field. METHODS:RCT manuscripts in the field of brain injury were identified using two readily-ava...

journal_title：BMC medical research methodology

authors： Borsody MK,Yamada C

更新日期：2005-02-07 00:00:00

abstract：BACKGROUND:Video stimulated recall (VSR) is a method of enhancing participants' accounts of the consultation using a video recording of the event to encourage and prompt recall in a post consultation interview. VSR is used in education and education research, and to a lesser extent in medical and nursing research. Litt...

journal_title：BMC medical research methodology

authors： Paskins Z,McHugh G,Hassell AB

更新日期：2014-08-30 00:00:00

abstract：BACKGROUND:This paper focuses on measuring the efficiency and effectiveness of two diagramming methods employed in key informant interviews with clinicians and health care administrators. The two methods are 'participatory diagramming', where the respondent creates a diagram that assists in their communication of answe...

journal_title：BMC medical research methodology

authors： Umoquit MJ,Dobrow MJ,Lemieux-Charles L,Ritvo PG,Urbach DR,Wodchis WP

更新日期：2008-08-08 00:00:00

abstract：BACKGROUND:Chemotherapy is expected to reduce cancer deaths (CD), while possibly being harmful in terms of non-cancer deaths (NCD) because of toxicity. Peto's log-rank test is popular in the medical literature, but its operating characteristics are barely known. We compared this test to the most common ones in the stat...

journal_title：BMC medical research methodology

authors： Rotolo F,Michiels S

更新日期：2014-05-29 00:00:00

abstract：BACKGROUND:The Behavioral Risk Factor Surveillance System (BRFSS) is a network of health-related telephone surveys--conducted by all 50 states, the District of Columbia, and participating US territories-that receive technical assistance from CDC. Data users often aggregate BRFSS state samples for national estimates wit...

journal_title：BMC medical research methodology

authors： Iachan R,Pierannunzi C,Healey K,Greenlund KJ,Town M

更新日期：2016-11-15 00:00:00

abstract：BACKGROUND:Cluster randomised controlled trials (CRCTs) are frequently used in health service evaluation. Assuming an average cluster size, required sample sizes are readily computed for both binary and continuous outcomes, by estimating a design effect or inflation factor. However, where the number of clusters are fix...

journal_title：BMC medical research methodology

authors： Hemming K,Girling AJ,Sitch AJ,Marsh J,Lilford RJ

更新日期：2011-06-30 00:00:00

abstract：BACKGROUND:Syntheses of qualitative studies can inform health policy, services and our understanding of patient experience. Meta-ethnography is a systematic seven-phase interpretive qualitative synthesis approach well-suited to producing new theories and conceptual models. However, there are concerns about the quality ...

journal_title：BMC medical research methodology

authors： France EF,Ring N,Thomas R,Noyes J,Maxwell M,Jepson R

更新日期：2014-11-19 00:00:00

abstract：BACKGROUND:Outcomes in observational studies may not best estimate those expected in the HIV vaccine efficacy trials. We compared retention in Simulated HIV Vaccine Efficacy Trials (SiVETs) and observational cohorts drawn from two key populations in Uganda. METHODS:Two SiVETs were nested within two observational cohor...

journal_title：BMC medical research methodology

authors： Abaasa A,Todd J,Nash S,Mayanja Y,Kaleebu P,Fast PE,Price M

更新日期：2020-02-12 00:00:00

abstract：BACKGROUND:Most electronic search efforts directed at identifying primary studies for inclusion in systematic reviews rely on the optimal Boolean search features of search interfaces such as DIALOG and Ovid. Our objective is to test the ability of an Ultraseek search engine to rank MEDLINE records of the included studi...

journal_title：BMC medical research methodology

authors： Sampson M,Barrowman NJ,Moher D,Clifford TJ,Platt RW,Morrison A,Klassen TP,Zhang L

更新日期：2006-02-24 00:00:00

abstract：BACKGROUND:The occurrence of communicable diseases (CD) depends on exposure to contagious persons. The effects of exposure to CD are delayed in time and contagious persons remain contagious for several days during which their contagiousness varies. Moreover when multiple exposures occur, it is difficult to know which e...

journal_title：BMC medical research methodology

authors： Payet C,Voirin N,Vanhems P,Ecochard R

更新日期：2013-02-20 00:00:00

abstract：BACKGROUND:Growth Mixture Modeling (GMM) is commonly used to group individuals on their development over time, but convergence issues and impossible values are common. This can result in unreliable model estimates. Constraining variance parameters across classes or over time can solve these issues, but can also serious...

journal_title：BMC medical research methodology

authors： Sijbrandij JJ,Hoekstra T,Almansa J,Peeters M,Bültmann U,Reijneveld SA

更新日期：2020-11-12 00:00:00

abstract：BACKGROUND:Multi-centre randomized controlled clinical trials play an important role in modern evidence-based medicine. Advantages of collecting data from more than one site are numerous, including accelerated recruitment and increased generalisability of results. Mixed models can be applied to account for potential cl...

journal_title：BMC medical research methodology

authors： Harden M,Friede T

更新日期：2018-11-29 00:00:00

abstract：BACKGROUND:Statistical time series derived from administrative data sets form key indicators in measuring progress in addressing disadvantage in Aboriginal and Torres Strait Islander populations in Australia. However, inconsistencies in the reporting of Indigenous status can cause difficulties in producing reliable ind...

journal_title：BMC medical research methodology

authors： Lawrence D,Christensen D,Mitrou F,Draper G,Davis G,McKeown S,McAullay D,Pearson G,Zubrick SR

更新日期：2012-07-02 00:00:00

abstract：BACKGROUND:Regular and timely monitoring of blood glucose (BG) levels in hospitalized patients with diabetes mellitus is crucial to optimizing inpatient glycaemic control. However, methods to quantify timeliness as a measurement of quality of care are lacking. We propose an analytical approach that utilizes BG measurem...

journal_title：BMC medical research methodology

authors： Chen Y,Kao SL,Tai ES,Wee HL,Khoo EY,Ning Y,Salloway MK,Deng X,Tan CS

更新日期：2016-04-08 00:00:00

abstract：BACKGROUND:Mediation is an important issue considered in the behavioral, medical, and social sciences. It addresses situations where the effect of a predictor variable X on an outcome variable Y is explained to some extent by an intervening, mediator variable M. Methods for addressing mediation have been available for ...

journal_title：BMC medical research methodology

authors： Knafl GJ,Knafl KA,Grey M,Dixon J,Deatrick JA,Gallo AM

更新日期：2017-03-21 00:00:00

abstract：BACKGROUND:Studies in both paediatric and psychiatric settings often experience problems in recruitment. This can compromise the ability of the study to recruit to target, meaning studies are potentially underpowered. It can also result in a biased sample if a non-representative group are selectively recruited. Recruit...

journal_title：BMC medical research methodology

authors： Loades ME,Smith L,Higson-Sweeney N,Beasant L,Stallard P,Kessler D,Crawley E

更新日期：2019-04-27 00:00:00

abstract：BACKGROUND:The study design and protocol that underpin a randomised controlled trial (RCT) are critical for the ultimate success of the trial. Although RCTs are considered the gold standard for research, there are multiple threats to their validity such as participant recruitment and retention, identifying a meaningful...

journal_title：BMC medical research methodology

authors： Hall CL,Brown S,James M,Martin JL,Brown N,Selby K,Clarke J,Williams L,Sayal K,Hollis C,Groom MJ

更新日期：2019-06-18 00:00:00

abstract：BACKGROUND:Given an observed test statistic and its degrees of freedom, one may compute the observed P value with most statistical packages. It is unknown to what extent test statistics and P values are congruent in published medical papers. METHODS:We checked the congruence of statistical results reported in all the ...

journal_title：BMC medical research methodology

authors： García-Berthou E,Alcaraz C

更新日期：2004-05-28 00:00:00

abstract：BACKGROUND:Health researchers undertake studies which combine qualitative and quantitative methods. Little attention has been paid to the structural issues affecting this mixed methods approach. We explored the facilitators and barriers to undertaking mixed methods studies in health research. METHODS:Face-to-face semi...

journal_title：BMC medical research methodology

authors： O'Cathain A,Nicholl J,Murphy E

更新日期：2009-12-09 00:00:00

abstract：BACKGROUND:Sickness absence (SA) is an important social, economic and public health issue. Identifying and understanding the determinants, whether biological, regulatory or, health services-related, of variability in SA duration is essential for better management of SA. The conditional frailty model (CFM) is useful whe...

journal_title：BMC medical research methodology

authors： Torá-Rocamora I,Gimeno D,Delclos G,Benavides FG,Manzanera R,Jardí J,Alberti C,Yasui Y,Martínez JM

更新日期：2013-09-16 00:00:00

abstract：BACKGROUND:Bias in adolescent self-reported height and weight is well documented. Given the importance and widespread use of the National Longitudinal Study of Adolescent to Adult Health (Add Health) data for obesity research, we developed and tested the feasibility and validity of an empirically derived statistical co...

journal_title：BMC medical research methodology

authors： Liechty JM,Bi X,Qu A

更新日期：2016-09-22 00:00:00

abstract：BACKGROUND:The "real" effect size of a medical therapy is constant over time. In contrast, the effect size reported in randomised controlled trials (RCTs) may change over time because the sum of all kinds of bias influencing the reported effectiveness is not necessarily constant. As this would affect the validity of me...

journal_title：BMC medical research methodology

authors： Gehr BT,Weiss C,Porzsolt F

更新日期：2006-05-11 00:00:00

abstract：BACKGROUND:Dynamic risk models, which incorporate disease-free survival and repeated measurements over time, might yield more accurate predictions of future health status compared to static models. The objective of this study was to develop and apply a dynamic prediction model to estimate the risk of developing type 2 ...

journal_title：BMC medical research methodology

authors： Parast L,Mathews M,Friedberg MW

更新日期：2019-08-14 00:00:00

abstract：BACKGROUND:Systematic reviews often require substantial resources, partially due to the large number of records identified during searching. Although artificial intelligence may not be ready to fully replace human reviewers, it may accelerate and reduce the screening burden. Using DistillerSR (May 2020 release), we eva...

journal_title：BMC medical research methodology

authors： Hamel C,Kelly SE,Thavorn K,Rice DB,Wells GA,Hutton B

更新日期：2020-10-15 00:00:00

abstract：BACKGROUND:Exposure to unhealthy environments and inadequate child stimulation are main risk factors that affect children's health and wellbeing in low- and middle-income countries. Interventions that simultaneously address several risk factors at the household level have great potential to reduce these negative effect...

journal_title：BMC medical research methodology

authors： Hartinger SM,Nuño N,Hattendorf J,Verastegui H,Karlen W,Ortiz M,Mäusezahl D

更新日期：2020-04-02 00:00:00

abstract：BACKGROUND:It is notoriously difficult to recruit patients to randomised controlled trials in primary care. This is particularly true when the disease process under investigation occurs relatively infrequently and must be investigated during a brief time window. Bell's palsy, an acute unilateral paralysis of the facial...

journal_title：BMC medical research methodology

authors： McKinstry B,Hammersley V,Daly F,Sullivan F

更新日期：2007-03-28 00:00:00