Helen M. Parsons

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Classifying nuclear magnetic resonance (NMR) spectra is a crucial step in many metabolomics experiments. Since several multivariate classification techniques depend upon the variance of the data, it is important to first minimise any contribution from unwanted technical variance arising from sample preparation and analytical measurements, and thereby(More)
The Hawthorne effect in experimental research is the unwanted effect of the experimental operations themselves. Following the Hawthorne studies, various explanations have been proposed to account for rising rates of production. Although in the Relay Assembly Test Room experiment the experimental operations may have produced other extraneous variables, a(More)
CONTEXT Among patients surgically treated for colon cancer, better survival has been demonstrated in those with more lymph nodes evaluated. The presumed mechanism behind this association suggests that a more extensive lymph node evaluation reduces the risk of understaging, leading to improved survival. OBJECTIVE To further evaluate the mechanism behind(More)
BACKGROUND Periprosthetic infection about the knee is a devastating complication that may affect between 1% and 5% of knee replacement. With over 79 000 knee replacements being implanted each year in the UK, periprosthetic infection (PJI) is set to become an important burden of disease and cost to the healthcare economy. One of the important controversies(More)
BACKGROUND Resections for elderly colorectal cancer (CRC) are forecasted to grow, particularly in those beyond the age limit of screening (>80 years). However, literature on operative outcomes after CRC procedures in the oldest old is focused primarily on operative mortality. We hypothesize that older age will additionally impact operative morbidity after(More)
IMPORTANCE Optimization of surgical outcomes after colectomy continues to be actively studied, but most studies group right-sided and left-sided colectomies together. OBJECTIVE To determine whether the complication rate differs between right-sided and left-sided colectomies for cancer. As a secondary analysis, we investigated hospital length of stay. (More)
Prior literature shows demographic differences in patients surgically treated for pancreatic cancer (PC). We hypothesized that socioeconomic disparities also exist across all aspects of PC care, in both surgically and non-surgically treated patients. We identified a cohort of patients with American Joint Committee on Cancer (AJCC) stage I–IV PC in the(More)
Mortality and complications following bariatric surgery occur at acceptable rates, but its safety in the elderly population is unknown. We hypothesized that short-term operative outcomes in bariatric surgery patients ≥65 years would be comparable to younger persons. Patients with a body mass index ≥35 kg/m2 who underwent bariatric surgery in the 2005–2009(More)
PURPOSE After the National Institutes of Health Consensus Statement in 1990, breast-conserving surgery (BCS) became more common while mastectomy rates decreased. However, several recently published single-institution studies have reported an increase in mastectomy rates in the past decade. We conducted a population-based study to evaluate national trends in(More)
BACKGROUND Inadequate access has contributed to widespread racial disparities in cancer care in the United States. However, the outcomes for racial minorities at quality-seeking hospitals, such as those participating in the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP), remain unknown. We hypothesized that operative(More)