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Dr. Barrett  Wallis  Md image

Dr. Barrett Wallis Md

6152 W Corporate Oaks Dr
Crystal River FL 34429
352 643-3900
Medical School: Other - 1979
Accepts Medicare: Yes
Participates In eRX: Yes
Participates In PQRS: Yes
Participates In EHR: No
License #: ME48685
NPI: 1740220938
Taxonomy Codes:
207RG0100X

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Awards & Recognitions

About Us

Practice Philosophy

Conditions

Dr. Barrett Wallis is associated with these group practices

Procedure Pricing

HCPCS Code Description Average Price Average Price
Allowed By Medicare
HCPCS Code:45385 Description:Lesion removal colonoscopy Average Price:$1,088.96 Average Price Allowed
By Medicare:
$264.69
HCPCS Code:45383 Description:Lesion removal colonoscopy Average Price:$1,159.00 Average Price Allowed
By Medicare:
$354.65
HCPCS Code:45384 Description:Lesion remove colonoscopy Average Price:$954.00 Average Price Allowed
By Medicare:
$197.82
HCPCS Code:45380 Description:Colonoscopy and biopsy Average Price:$961.26 Average Price Allowed
By Medicare:
$213.34
HCPCS Code:43239 Description:Upper gi endoscopy biopsy Average Price:$697.60 Average Price Allowed
By Medicare:
$119.33
HCPCS Code:43235 Description:Uppr gi endoscopy diagnosis Average Price:$602.00 Average Price Allowed
By Medicare:
$145.64
HCPCS Code:99291 Description:Critical care first hour Average Price:$547.79 Average Price Allowed
By Medicare:
$221.88
HCPCS Code:43248 Description:Uppr gi endoscopy/guide wire Average Price:$400.00 Average Price Allowed
By Medicare:
$167.03
HCPCS Code:99223 Description:Initial hospital care Average Price:$397.69 Average Price Allowed
By Medicare:
$199.10
HCPCS Code:43249 Description:Esoph endoscopy dilation Average Price:$369.00 Average Price Allowed
By Medicare:
$176.44
HCPCS Code:99204 Description:Office/outpatient visit new Average Price:$323.00 Average Price Allowed
By Medicare:
$162.72
HCPCS Code:99203 Description:Office/outpatient visit new Average Price:$209.00 Average Price Allowed
By Medicare:
$106.14
HCPCS Code:99214 Description:Office/outpatient visit est Average Price:$206.01 Average Price Allowed
By Medicare:
$104.45
HCPCS Code:99233 Description:Subsequent hospital care Average Price:$202.42 Average Price Allowed
By Medicare:
$101.44
HCPCS Code:99232 Description:Subsequent hospital care Average Price:$141.00 Average Price Allowed
By Medicare:
$70.65
HCPCS Code:99213 Description:Office/outpatient visit est Average Price:$139.00 Average Price Allowed
By Medicare:
$70.65
HCPCS Code:99212 Description:Office/outpatient visit est Average Price:$82.92 Average Price Allowed
By Medicare:
$42.50

HCPCS Code Definitions

99204
Office or other outpatient visit for the evaluation and management of a new patient, which requires these 3 key components: A comprehensive history; A comprehensive examination; Medical decision making of moderate complexity. Counseling and/or coordination of care with other physicians, other qualified health care professionals, or agencies are provided consistent with the nature of the problem(s) and the patient's and/or family's needs. Usually, the presenting problem(s) are of moderate to high severity. Typically, 45 minutes are spent face-to-face with the patient and/or family.
99232
Subsequent hospital care, per day, for the evaluation and management of a patient, which requires at least 2 of these 3 key components: An expanded problem focused interval history; An expanded problem focused examination; Medical decision making of moderate complexity. Counseling and/or coordination of care with other physicians, other qualified health care professionals, or agencies are provided consistent with the nature of the problem(s) and the patient's and/or family's needs. Usually, the patient is responding inadequately to therapy or has developed a minor complication. Typically, 25 minutes are spent at the bedside and on the patient's hospital floor or unit.
99213
Office or other outpatient visit for the evaluation and management of an established patient, which requires at least 2 of these 3 key components: An expanded problem focused history; An expanded problem focused examination; Medical decision making of low complexity. Counseling and coordination of care with other physicians, other qualified health care professionals, or agencies are provided consistent with the nature of the problem(s) and the patient's and/or family's needs. Usually, the presenting problem(s) are of low to moderate severity. Typically, 15 minutes are spent face-to-face with the patient and/or family.
99212
Office or other outpatient visit for the evaluation and management of an established patient, which requires at least 2 of these 3 key components: A problem focused history; A problem focused examination; Straightforward medical decision making. Counseling and/or coordination of care with other physicians, other qualified health care professionals, or agencies are provided consistent with the nature of the problem(s) and the patient's and/or family's needs. Usually, the presenting problem(s) are self limited or minor. Typically, 10 minutes are spent face-to-face with the patient and/or family.
99223
Initial hospital care, per day, for the evaluation and management of a patient, which requires these 3 key components: A comprehensive history; A comprehensive examination; and Medical decision making of high complexity. Counseling and/or coordination of care with other physicians, other qualified health care professionals, or agencies are provided consistent with the nature of the problem(s) and the patient's and/or family's needs. Usually, the problem(s) requiring admission are of high severity. Typically, 70 minutes are spent at the bedside and on the patient's hospital floor or unit.
99214
Office or other outpatient visit for the evaluation and management of an established patient, which requires at least 2 of these 3 key components: A detailed history; A detailed examination; Medical decision making of moderate complexity. Counseling and/or coordination of care with other physicians, other qualified health care professionals, or agencies are provided consistent with the nature of the problem(s) and the patient's and/or family's needs. Usually, the presenting problem(s) are of moderate to high severity. Typically, 25 minutes are spent face-to-face with the patient and/or family.
99233
Subsequent hospital care, per day, for the evaluation and management of a patient, which requires at least 2 of these 3 key components: A detailed interval history; A detailed examination; Medical decision making of high complexity. Counseling and/or coordination of care with other physicians, other qualified health care professionals, or agencies are provided consistent with the nature of the problem(s) and the patient's and/or family's needs. Usually, the patient is unstable or has developed a significant complication or a significant new problem. Typically, 35 minutes are spent at the bedside and on the patient's hospital floor or unit.
99291
Critical care, evaluation and management of the critically ill or critically injured patient; first 30-74 minutes
43235
Esophagogastroduodenoscopy, flexible, transoral; diagnostic, including collection of specimen(s) by brushing or washing, when performed (separate procedure)
99203
Office or other outpatient visit for the evaluation and management of a new patient, which requires these 3 key components: A detailed history; A detailed examination; Medical decision making of low complexity. Counseling and/or coordination of care with other physicians, other qualified health care professionals, or agencies are provided consistent with the nature of the problem(s) and the patient's and/or family's needs. Usually, the presenting problem(s) are of moderate severity. Typically, 30 minutes are spent face-to-face with the patient and/or family.
43249
Esophagogastroduodenoscopy, flexible, transoral; with transendoscopic balloon dilation of esophagus (less than 30 mm diameter)
45380
Colonoscopy, flexible, proximal to splenic flexure; with biopsy, single or multiple
43248
Esophagogastroduodenoscopy, flexible, transoral; with insertion of guide wire followed by passage of dilator(s) through esophagus over guide wire
43239
Esophagogastroduodenoscopy, flexible, transoral; with biopsy, single or multiple
45385
Colonoscopy, flexible, proximal to splenic flexure; with removal of tumor(s), polyp(s), or other lesion(s) by snare technique
45384
Colonoscopy, flexible, proximal to splenic flexure; with removal of tumor(s), polyp(s), or other lesion(s) by hot biopsy forceps or bipolar cautery

Medical Malpractice Cases

None Found

Medical Board Sanctions

None Found

Referrals

NPI
Doctor Name
Specialty
Count
1639132269
Medical Oncology
2,828
1972552065
Diagnostic Radiology
1,877
1609802792
Internal Medicine
1,419
1215975719
Diagnostic Radiology
1,362
1093706145
Diagnostic Radiology
1,210
1073695755
Internal Medicine
877
1316041064
Hematology/Oncology
796
1194790857
Internal Medicine
782
1407850365
Internal Medicine
772
1326060716
Family Practice
733
*These referrals represent the top 10 that Dr. Wallis has made to other doctors

Publications

Assessment of a carbon dioxide laser for the measurement of thermal nociceptive thresholds following intramuscular administration of analgesic drugs in pain-free female cats. - Veterinary anaesthesia and analgesia
To assess the potential of a thermal carbon dioxide (CO2 ) laser to explore antinociception in pain-free cats.Experimental, prospective, blinded, randomized study.Sixty healthy adult female cats with a (mean ± standard deviation) weight of 3.3 ± 0.6 kg.Cats were systematically allocated to one of six treatments: saline 0.2 mL per cat; morphine 0.5 mg kg(-1) ; buprenorphine 20 μg kg(-1) ; medetomidine 2 μg kg(-1) ; tramadol 2 mg kg(-1) , and ketoprofen 2 mg kg(-1) . Latency to respond to thermal stimulation was assessed at baseline and at intervals of 15-30, 30-45, 45-60, 60-75, 90-105 and 120-135 minutes. Thermal thresholds were assessed using time to respond behaviourally to stimulation with a 500 mW CO2 laser. Within-treatment differences in response latency were assessed using Friedman's test. Differences amongst treatments were assessed using independent Kruskal-Wallis tests. Where significant effects were identified, pairwise comparisons were conducted to elucidate the direction of the effect.Cats treated with morphine (χ(2)  = 12.90, df = 6, p = 0.045) and tramadol (χ(2)  = 20.28, df = 6, p = 0.002) showed significant increases in latency to respond. However, subsequent pairwise comparisons indicated that differences in latencies at specific time-points were significant (p < 0.05) only for tramadol at 60-75 and 90-105 minutes after administration (21.9 and 43.6 seconds, respectively) in comparison with baseline (11.0 seconds). No significant pairwise comparisons were found within the morphine treatment. Injections of saline, ketoprofen, medetomidine or buprenorphine showed no significant effect on latency to respond.The CO2 laser technique may have utility in the assessment of thermal nociceptive thresholds in pain-free cats after analgesic administration and may provide a simpler alternative to existing systems. Further exploration is required to examine its sensitivity and comparative utility.© 2015 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.
Age and psychological influences on immune responses to trivalent inactivated influenza vaccine in the meditation or exercise for preventing acute respiratory infection (MEPARI) trial. - Human vaccines & immunotherapeutics
Strategies to improve influenza vaccine protection among elderly individuals are an important research priority. Mindfulness-based stress reduction (MBSR) and exercise have been shown to affect aspects of immune function in some populations. We hypothesized that influenza vaccine responses may be enhanced with meditation or exercise training as compared with controls.No differences in vaccine responses were found comparing control to MBSR or exercise. Individuals achieving seroprotective levels of influenza antibody ≥160 units had higher optimism, less anxiety, and lower perceived stress than the nonresponders. Age correlated with influenza antibody responses, but not with IFNγ or IL-10 production.The MBSR and exercise training evaluated in this study failed to enhance immune responses to influenza vaccine. However, optimism, perceived stress, and anxiety were correlated in the expected directions with antibody responses to influenza vaccine.Healthy individuals≥50 y were randomly assigned to exercise (n=47) or MBSR (n=51) training or a waitlist control condition (n=51). Each participant received trivalent inactivated influenza vaccine after 6 weeks, and had blood draws prior to and 3 and 12 weeks after immunization. Serum influenza antibody, nasal immunoglobulin A, and peripheral blood mononuclear cell interferon-γ (IFNγ) and interleukin-10 (IL-10) concentrations were measured. Measures of optimism, perceived stress, and anxiety were obtained over the course of the study. Seroprotection was defined as an influenza antibody concentration≥160 units. Vaccine responses were compared using ANOVA, t tests, and Kruskal-Wallis tests. The correlation between vaccine responses and age was examined with the Pearson test.
The zebrafish reference genome sequence and its relationship to the human genome. - Nature
Zebrafish have become a popular organism for the study of vertebrate gene function. The virtually transparent embryos of this species, and the ability to accelerate genetic studies by gene knockdown or overexpression, have led to the widespread use of zebrafish in the detailed investigation of vertebrate gene function and increasingly, the study of human genetic disease. However, for effective modelling of human genetic disease it is important to understand the extent to which zebrafish genes and gene structures are related to orthologous human genes. To examine this, we generated a high-quality sequence assembly of the zebrafish genome, made up of an overlapping set of completely sequenced large-insert clones that were ordered and oriented using a high-resolution high-density meiotic map. Detailed automatic and manual annotation provides evidence of more than 26,000 protein-coding genes, the largest gene set of any vertebrate so far sequenced. Comparison to the human reference genome shows that approximately 70% of human genes have at least one obvious zebrafish orthologue. In addition, the high quality of this genome assembly provides a clearer understanding of key genomic features such as a unique repeat content, a scarcity of pseudogenes, an enrichment of zebrafish-specific genes on chromosome 4 and chromosomal regions that influence sex determination.
A randomized, placebo-controlled trial of ondansetron, metoclopramide, and promethazine in adults. - The American journal of emergency medicine
The objective of the study was to assess whether ondansetron has superior nausea reduction compared with metoclopramide, promethazine, or saline placebo in emergency department (ED) adults.This randomized, placebo-controlled, double-blinded superiority trial was intended to enroll a convenience sample of 600 patients. Nausea was evaluated on a 100-mm visual analog scale (VAS) at baseline and 30 minutes after treatment. Patients with a minimum preenrollment VAS of 40 mm were randomized to intravenous ondansetron 4 mg, metoclopramide 10 mg, promethazine 12.5 mg, or saline placebo. A 12-mm VAS improvement in nausea severity was deemed clinically important. We measured potential drug adverse effects at baseline and 30 minutes. Patients received approximately 500 mL of saline hydration during the initial 30 minutes.Of 180 subjects who consented, 163 completed the study. The median age was 32 years (interquartile range, 23-47), and 68% were female. The median 30-minute VAS reductions (95% confidence intervals) and saline volume given for ondansetron, metoclopramide, promethazine, and saline were -22 (-32 to -15), -30 (-38 to -25.5), -29 (-40 to -21), and -16 (-25 to -3), and 500, 500, 500, and 450, respectively. The median 30-minute VAS differences (95% confidence intervals) between ondansetron and metoclopramide, promethazine, and saline were -8 (-18.5 to 3), -7 (-21 to -5.5), and 6 (-7 to 20), respectively. We compared the antiemetic efficacy across all treatments with the Kruskal-Wallis test (P = .16).Our study shows no evidence that ondansetron is superior to metoclopramide and promethazine in reducing nausea in ED adults. Early study termination may have limited detection of ondansetron's superior nausea reduction over saline.Copyright © 2011 Elsevier Inc. All rights reserved.
Correlation of serum CA125 with stage, grade and survival of patients with epithelial ovarian cancer at a single centre. - Irish medical journal
To evaluate the relationship between serum CA125 tumour marker level before and after surgery of epithelial ovarian carcinoma and assess its potential role as a prognostic factor. A retrospective review of 87 patients with epithelial ovarian carcinoma at a single centre between January 2001 and December 2005 was performed. Serum CA125 levels were assessed for their relationship to pathological stage, tumour grade, tumour volume and age as well as overall survival. A total of 75 patients, mean age 58.94 years and median follow-up of 24 months were included in the analysis. While the preoperative CA125 level did not correlate significantly with stage, tumour grade or survival, the postoperative CA125 correlated to FIGO stage (p<0.0001), tumour grade (p<0.0001) and overall survival (p=0.01). Reduced survival was noted with increasing age at the time of surgery (p=0.009) and bulk of the residual disease postoperatively (p=0.011).
Hormone replacement therapy and false positive recall in the Million Women Study: patterns of use, hormonal constituents and consistency of effect. - Breast cancer research : BCR
Current and recent users of hormone replacement therapy (HRT) have an increased risk of being recalled to assessment at mammography without breast cancer being diagnosed ('false positive recall'), but there is limited information on the effects of different patterns of HRT use on this. The aim of this study is to investigate in detail the relationship between patterns of use of HRT and false positive recall.A total of 87,967 postmenopausal women aged 50 to 64 years attending routine breast cancer screening at 10 UK National Health Service Breast Screening Units from 1996 to 1998 joined the Million Women Study by completing a questionnaire before screening and were followed for their screening outcome.Overall, 399 (0.5%) participants were diagnosed with breast cancer and 2,629 (3.0%) had false positive recall. Compared to never users of HRT, the adjusted relative risk (95% CI) of false positive recall was: 1.62 (1.43-1.83), 1.80 (1.62-2.01) and 0.76 (0.52-1.10) in current users of oestrogen-only HRT, oestrogen-progestagen HRT and tibolone, respectively (p (heterogeneity) < 0.0001); 1.65 (1.43-1.91), 1.49 (1.22-1.81) and 2.11 (1.45-3.07) for current HRT used orally, transdermally or via an implant, respectively (p (heterogeneity) = 0.2); and 1.84 (1.67-2.04) and 1.75 (1.49-2.06) for sequential and continuous oestrogen-progestagen HRT, respectively (p (heterogeneity) = 0.6). The relative risk of false positive recall among current users appeared to increase with increasing time since menopause, but did not vary significantly according to any other factors examined, including duration of use, hormonal constituents, dose, whether single- or two-view screening was used, or the woman's personal characteristics.Current use of oestrogen-only and oestrogen-progestagen HRT, but not tibolone, increases the risk of false positive recall at screening.
Heating and humidifying of carbon dioxide during pneumoperitoneum is not indicated: a prospective randomized trial. - Surgical endoscopy
Carbon dioxide (CO2) pneumoperitoneum usually is created by a compressed gas source. This exposes the patient to cool dry gas delivered at room temperature (21 degrees C) with 0% relative humidity. Various delivery methods are available for humidifying and heating CO2 gas. This study was designed to determine the effects of heating and humidifying gas for the intraabdominal environment.For this study, 44 patients undergoing laparoscopic Roux-en-Y gastric bypass were randomly assigned to one of four arms in a prospective, randomized, single-blinded fashion: raw CO2 (group 1), heated CO2 (group 2), humidified CO2 (group 3), and heated and humidified CO2 (group 4). A commercially available CO2 heater-humidifier was used. Core temperatures, intraabdominal humidity, perioperative data, and postoperative outcomes were monitored. Peritoneal biopsies were taken in each group at the beginning and end of the case. Biopsies were subjected staining protocols designed to identify structural damage and macrophage activity. Postoperative narcotic use, pain scale scores, recovery room time, and length of hospital stay were recorded. One-way analysis of variance (ANOVA) and the nonparametric Kruskal-Wallis test were used to compare the groups.Demographics, volume of CO2 used, intraabdominal humidity, bladder temperatures, lens fogging, and operative times were not significantly different between the groups. Core temperatures were stable, and intraabdominal humidity measurements approached 100% for all the patients over the entire procedure. Total narcotic dosage and pain scale scores were not statistically different. Recovery room times and length of hospital stay were similar in all the groups. Only one biopsy in the heated-humidified group showed an increase in macrophage activity.The intraabdominal environment in terms of temperature and humidity was similar in all the groups. There was no significant difference in the intraoperative body temperatures or the postoperative variable measured. No histologic changes were identified. Heating or humidifying of CO2 is not justified for patients undergoing laparoscopic bariatric surgery.
The microvasculature in insulin resistance and type 2 diabetes. - Seminars in vascular medicine
Insulin resistance of muscle has been attributed to impairment of elements of insulin signaling, glucose transport, and/or metabolism within the muscle cells. This article explores the notion that a component of insulin resistance in vivo may result from impaired hemodynamic effects of this hormone to facilitate access to the muscle cells for itself and other nutrients, including glucose. In chronic situations this may manifest as a decreased capillary density of muscle, but in the acute, there may be impaired mechanisms for increasing total limb blood flow or for achieving optimal microvascular perfusion. Newly developed techniques show that insulin acts to recruit muscle capillary flow to enhance microvascular perfusion in animals and humans. This microvascular effect of insulin correlates closely with muscle glucose uptake, is independent of increases in bulk blood flow, and is impaired in obese insulin-resistant patients. Similarly, there are impaired vasodilatory responses in the skin of diabetic subjects.
Influence of personal characteristics of individual women on sensitivity and specificity of mammography in the Million Women Study: cohort study. - BMJ (Clinical research ed.)
To examine how lifestyle, hormonal, and other factors influence the sensitivity and specificity of mammography.Women recruited into the Million Women Study completed a questionnaire about various personal factors before routine mammographic screening. A sample of 122,355 women aged 50-64 years were followed for outcome of screening and incident breast cancer in the next 12 months. Sensitivity and specificity were calculated by using standard definitions, with adjustment for potential confounding factors.Breast cancer was diagnosed in 726 (0.6%) women, 629 in screen positive and 97 in screen negative women; 3885 (3.2%) were screen positive but had no subsequent diagnosis of breast cancer. Overall sensitivity was 86.6% and specificity was 96.8%. Three factors had an adverse effect on both measures: use of hormone replacement therapy (sensitivity: 83.0% (95% confidence interval 77.4% to 87.6%), 84.7% (73.9% to 91.6%), and 92.1% (87.6% to 95.0%); specificity: 96.8% (96.6% to 97.0%), 97.8% (97.5% to 98.0%), and 98.1% (98.0% to 98.2%), respectively, for current, past, and never use); previous breast surgery v no previous breast surgery (sensitivity: 83.5% (75.7% to 89.1%) v 89.4% (86.5% to 91.8%); specificity: 96.2% (95.8% to 96.5%) v 97.4% (97.3% to 97.5%), respectively); and body mass index < 25 v > or = 25 (sensitivity: 85.7% (81.2% to 89.3%) v 91.0% (87.5% to 93.6%); specificity: 97.2% (97.0% to 97.3%) v 97.4% (97.3% to 97.6%), respectively). Neither sensitivity nor specificity varied significantly according to age, family history of breast cancer, parity, past oral contraceptive use, tubal ligation, physical activity, smoking, or alcohol consumption.The efficiency, and possibly the effectiveness, of mammographic screening is lower in users of hormone replacement therapy, in women with previous breast surgery, and in thin women compared with other women.
Characterization of a novel group of mycobacteria and proposal of Mycobacterium sherrisii sp. nov. - Journal of clinical microbiology
We describe here the characterization of five isolates of Mycobacterium simiae-like organisms representing a novel group based on whole-cell fatty acid analysis and genotypic evaluation. Two of the five isolates in this study, W55 and W58, were previously considered to belong to M. simiae serotype 2. Analysis of cellular fatty acids by gas-liquid chromatography indicated a close clustering of this group, which was well differentiated from the other M. simiae-like species. Molecular characterization was performed by nucleic acid sequencing of the small subunit rRNA gene and the gene encoding the 65-kDa heat shock protein and genomic DNA hybridization. Sequence analysis of the entire 16S rRNA gene showed a unique sequence most closely related to those of M. triplex and M. simiae. The hsp65 partial gene sequence was identical for the five isolates, with 97% identity to the M. simiae type strain. However, qualitative whole genomic DNA hybridization analysis confirmed that this group is genetically distinct from M. simiae and M. triplex. Antimicrobial susceptibilities for this group resemble those of M. simiae and M. lentiflavum. We conclude that this group represents a unique Mycobacterium species for which we propose the name Mycobacterium sherrisii sp. nov.

Map & Directions

6152 W Corporate Oaks Dr Crystal River, FL 34429
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