PubMed Health⌕ Search

Biomedical subjects

N J Shaheen

Publications and source records attributed to N J Shaheen.

At least 19 recordsLinked to original sources
PubMed2004

What is the best management strategy for high grade dysplasia in Barrett's oesophagus? A cost effectiveness analysis.

BACKGROUND: Multiple treatment strategies for subjects with high grade dysplasia (HGD) in Barrett's oesophagus (BO) have been suggested. However, it is unclear which of these strategies provides the greatest life expectancy, and the costs associated with the management strategies are unknown. AIM: To compare the efficacy and cost effectiveness of competing management strategies for BO with HGD. METHODS: We created a decision analysis model in Data 4.0 to assess possible treatment strategies for BO with HGD. The strategies included: (1) no preventative strategy, (2) elective surgical oesophagectomy, (3) endoscopic ablation, and (4) surveillance endoscopy. The base case was a healthy 50 year old White male with an initial diagnosis of BO with HGD. The model allowed for complications of surgery, including death. Ablative therapy could cause stricture or perforation. Pathological misinterpretation was allowed, and modelled after reported rates. Estimates were derived from the literature for the rate of progression of HGD to cancer and for complication rates for the various treatment modalities. The endoscopic ablation arm was modelled as photodynamic therapy. Sensitivity analyses were performed over a wide range of cancer incidences, complication rates, and procedure costs. RESULTS: Endoscopic ablation was the most effective strategy, yielding 15.5 discounted quality adjusted life years (dQALY), compared with 15.0 for endoscopic surveillance and 14.9 for oesophagectomy. No preventative strategy was the most inexpensive option, yielding an average cost per quality adjusted life year of US dollars 54 (44) per dQALY, but resulted in high rates of cancer. Endoscopic surveillance dominated oesophagectomy, being both less costly and more effective. The condition of extended dominance occurred when comparing endoscopic ablation to endoscopic surveillance because, although the total costs of ablation were greater than those of surveillance, it was less expensive to buy an additional life year using endoscopic ablation than endoscopic surveillance. The incremental cost effectiveness ratio when moving from no therapy to ablative therapy was a reasonable US dollars 25 621/dQALY (21 009/dQALY). Sensitivity analysis demonstrated that when yearly rates of progression to cancer from HGD exceeded 30%, oesophagectomy became the most cost effective option. CONCLUSIONS: A strategy of endoscopic ablation provided the longest quality adjusted life expectancy for BO with HGD. Although endoscopic surveillance was less expensive than endoscopic ablation, it was associated with shorter survival. Optimal utilisation of healthcare resources may be achieved with endoscopic ablative therapy for BO with HGD.

Barrett Esophagus↗
PubMed2001

The quality of care in Barrett's esophagus: endoscopist and pathologist practices.

BACKGROUND: The diagnosis of Barrett's esophagus (BE) has important psychological and economic implications. Although accepted standards for endoscopic biopsy methods and pathological interpretation for BE exist, adherence to these standards as a measure of the quality of care in BE has not been evaluated. Our aim was to assess the quality of care in BE by evaluating the process of care and adherence to accepted standards of practice. METHODS: Explicit process-of-care criteria were developed using a systematic literature review and expert opinion in four domains of care: the quality of biopsy methods, the adequacy in identifying endoscopic landmarks, endoscopist-pathologist communication, and pathological interpretation and reporting. We reviewed all endoscopy and pathology reports of BE patients at two institutions from 1994-1997. An academic medical center (N = 237) with staff endoscopists and an academically affiliated community hospital (N = 100) with private-practice endoscopists were analyzed. RESULTS: Physicians showed the highest adherence to accepted standards of care in the "adequacy of identifying landmarks" and "endoscopist-pathologist communication" domains, with a > or =70% adherence rate in most criteria. Conversely, physicians demonstrated the poorest adherence with the "quality of biopsy methods" and "pathologist interpretation and reporting" domains, with adherence rates frequently <60%. Significantly, biopsies were taken in the presence of visible esophagitis 35% of the time. Performance on several of the quality indicators varied significantly by the practice setting. CONCLUSIONS: We have identified several opportunities for quality improvement efforts. In every domain, there is room for improvement, particularly in the quality of biopsy methods. As initiatives to screen the large population of gastroesophageal reflux disease patients for BE may be imminent, the time is now to define the critical process-of-care measures to minimize the risk of overdiagnosis and inadequate endoscopic surveillance.

Barrett Esophagus↗
PubMed2000

Is there publication bias in the reporting of cancer risk in Barrett's esophagus?

BACKGROUND & AIMS: The published risk of adenocarcinoma in the setting of Barrett's esophagus (BE) varies. Publication bias, the selective reporting of studies featuring positive or extreme results, may result in overestimation of this cancer risk in the literature. The aim of this study was to assess those publications reporting a cancer risk in BE for evidence of publication bias. METHODS: A MEDLINE search for all published estimates between 1966 and 1998 of cancer risk in BE was performed. All studies reporting a cancer risk expressible in cancers per patient-year of follow-up were retrieved. Bibliographies of these studies were surveyed for additional estimates. All publications that required an initial endoscopy with histologic confirmation of BE and any cancer were included. The relationship of reported cancer risk to size of the study was assessed. Multivariable regression controlling for differences in definition of BE, as well as other study characteristics, was performed. The data were also analyzed by means of a funnel diagram, an epidemiologic method to assess publication bias. RESULTS: Five hundred fifty-four abstracts were reviewed. Twenty-seven publications met the stated criteria for inclusion. There was a strong correlation between cancer risk and the size of the study, with small studies reporting much higher risks of cancer than larger studies. This association persisted when differences in the definition of BE, retrospective vs. prospective nature of the study, surveillance interval, and the effect of cancer detected in the first year were considered. The funnel diagram analysis suggested publication bias. CONCLUSIONS: The cancer risk in BE may be overestimated in the literature due to publication bias.

Adenocarcinoma↗
PubMed2000

The practices and attitudes of primary care nurse practitioners and physician assistants with respect to colorectal cancer screening.

OBJECTIVES: Although nurse practitioners and physician assistants form a large and growing portion of the primary care workforce, little is known about their colorectal cancer screening practices. The aim of this study was to assess the colorectal cancer screening practices, training, and attitudes of nurse practitioners and physician assistants practicing primary care medicine. METHODS: All nurse practitioners (827) and physician assistants (1178) licensed by the Medical Board of the State of North Carolina were surveyed by mail. Both groups were further divided into primary care versus non-primary care by self-described roles. Self-reported practices, training, and attitudes with respect to colorectal cancer screening were elicited. RESULTS: Response rates were 71.4% and 61.2%, for nurse practitioners and physician assistants respectively. A total of 51.3% of nurse practitioners and 50.3% of physician assistants described themselves as adult primary care providers. No primary care nurse practitioners and only 3.8% of primary care physician assistants performed screening flexible sigmoidoscopy. However, 76% of primary care physician assistants and 69% of primary care nurse practitioners reported recommending screening flexible sigmoidoscopy. A total of 95% primary care physician assistants and 92% of primary care nurse practitioners reported performing fecal occult blood testing. Only 9.4% of physician assistants and 2.8% of nurse practitioners received any formal instruction in flexible sigmoidoscopy while in their training. Additionally, 41.4% of primary care physician assistants and 27.7% of primary care nurse practitioners reported that they would be interested in obtaining formal training in flexible sigmoidoscopy. CONCLUSIONS: Physician assistants and nurse practitioners are motivated, willing and underutilized groups with respect to CRC screening. Efforts to increase education and training of these professionals may improve the availability of CRC screening modalities.

Adult↗
PubMed1999

Hyoscyamine as a pharmacological adjunct in colonoscopy: a randomized, double blinded, placebo-controlled trial.

OBJECTIVE: Investigators have assessed the utility of antispasmodic agents in colonoscopy, with conflicting results. The aim of this study is to determine the effects of premedication with hyoscyamine, an anticholinergic antispasmodic, on outcomes in colonoscopy. METHODS: A total of 165 patients undergoing elective colonoscopy were randomized in a double blinded fashion to one of three arms: intravenous hyoscyamine (0.25 mg), oral hyoscyamine (0.25 mg), or placebo, administered 20-40 min before colonoscopy. Primary outcome measures included insertion time to cecum, patient's assessment of pain, and physician assessment of spasm. Secondary outcome measures included amount of analgesic medications used, total procedure time, amount and type of pathology visualized, and physician assessment of patient's pain. RESULTS: Bivariate analysis showed no difference between the three groups in insertion time (13.8 min, 14.8 min, and 13.8 min for placebo, intravenous hyoscyamine, and oral hyocyamine, respectively), analgesic medication necessary, or any other primary or secondary outcome variable. Multivariate analysis controlling for potential confounders also failed to demonstrate any differences between the groups. Women had higher procedure duration and analgesic requirement, and reported more pain than did men. CONCLUSIONS: This randomized, double blinded, placebo-controlled trial did not demonstrate efficacy of either intravenous or oral hyoscyamine as a premedication for colonoscopy.

Administration, Oral↗
PubMed1998

Clinical characteristics of hereditary hemochromatosis patients who lack the C282Y mutation.

Approximately 85% of patients with typical hereditary hemochromatosis (HH) are homozygous for the C282Y mutation (C282Y/C282Y) in the recently identified candidate gene for HH. However, some HH patients are instead homozygous for the wild-type allele (wt/wt) at this locus. These wt/wt patients may represent a phenotypically similar, but genotypically different, heritable trait, or may be unrecognized cases of secondary iron overload. The purpose of this study is to provide an in-depth analysis of the wt/wt HH patients identified in the original description of the HH gene, and to compare them with 62 patients from the same analysis who were homozygous for the C282Y mutation. Eighteen of the 21 wt/wt HH patients from the original study were assessed for 14 historical and laboratory variables, including previously unrecognized causes of secondary iron overload, the heritability of iron overload and liver disease, and other clinical characteristics. Ten of these 18 wt/wt HH patients (55.6%) were found to have previously unrecognized causes for secondary iron overload compared with 3 of 62 (4.8%) of the C282Y/C282Y patients (P < .001). The remaining 8 wt/wt patients had no recognizable etiology of secondary iron overload. None of the 18 wt/wt patients had a family history of iron overload or liver disease, compared with 58% of the C282Y/C282Y patients (P < .001). When compared with C282Y homozygotes, the 8 wt/wt patients without secondary iron overload had a higher presenting hepatic iron index (HII) (9.5 vs. 4.7; P = .01). We conclude that, in this series of patients, over half of the wt/wt HH patients possessed previously unrecognized causes of secondary iron overload, and therefore, may have been misdiagnoses. If these cases are excluded, the number of false-negative tests is decreased, and the sensitivity of the mutational analysis is increased. However, there is a subgroup of wt/wt patients who have typical hemochromatosis without an identifiable cause of secondary iron overload. These patients may have more severe iron loading than C282Y homozygotes.

Cohort Studies↗
PubMed1998

Is the hemochromatosis gene a modifier locus for cystic fibrosis?

The variable clinical manifestations of cystic fibrosis (CF) suggest the influence of modifier genes. For example, meconium ileus is present in approximately 10-15% of neonates with cystic fibrosis; however, the genetic and, or environmental factors that determine whether an individual will develop this complication have not been determined. We propose the HFE gene as a candidate modifier locus for CF based on (1) the suggestion of an association between the HLA loci and CF phenotypes; (2) the location of the HFE gene near the HLA loci and; (3) the similarity between the gastrointestinal manifestations of hereditary hemochromatosis and CF. We have determined the frequency of the C282Y and H63D mutations in a group of 89 CF patients who were homozygous for delta F508 and for whom meconium ileus status was known. The carrier frequency of C282Y among the CF patients with meconium ileus was significantly different from that of our unaffected control group (19.4% versus 7.7%). However, the difference between the meconium ileus and the nonmeconium ileus groups was not significant (19.4% versus 10.3%). There was no difference in the frequency of the H63D among the three groups that were studied. These data are suggestive of a relationship between the development of meconium ileus or other gastrointestinal diseases in CF and the HFE gene. Further study of a larger group of patients is warranted.

Adult↗
PubMed1998

Type I choledochal cyst in association with familial adenomatous polyposis.

Choledochal cysts and familial adenomatous polyposis are infrequent disorders that are often manifest in childhood or in early adult life. The rarity and early presentation of these diseases suggests a genetic basis, which has been established for familial polyposis but not for choledochal cysts. We report a case of a 26-yr-old woman with both disorders and offer an alternative genetics-based etiology for the formation of choledochal cysts.

Adenomatous Polyposis Coli↗