Appraising Evidence For Health And Social Care mosdt recen123t

Student Number: 109793 Appraising Evidence for Health and Social Care Plan The aim of this assignment is to evaluate practice critically to see where evidence is needed and use this as a basis for question Introduction Critical appraisal of evidence is vital in this day and age of evidence based healthcare According to chambers (1998) it is the “assessment of evidence by systematically reviewing it’s relevance validity and results to specific situations” and its importance becomes apparent when implementing changes in the workplace based on evidence Hek (1996) believes that all nurses should be aware of how to critique/evaluate research, which is not surprising considering the current environment of implementing evidence based practice It is a skill that should be used by all healthcare professionals before implementing change Areas of particular interest in critical appraisal are validity; are the results valid, reliability; what are the results, and applicability, can the results be applied locally (shef.ac.uk 1111) Area of Practice I work in a diagnostic imaging department where we perform various tests which involve administration of a radioisotope followed by either an imaging procedure or analysis of blood samples taken post administration (Gemmell H, Murray A, Sharp P 2005 et al) We perform a wide range of tests which primarily look at the function of organs with renal, cardiac and musculoskeletal work making up the majority -1- Student Number: 109793 Our tests allow the function of organs to be visualised and monitored; Due to the lack of active ingredients in the radiopharmaceuticals we use (Hartman N 2006) the radiopharmaceutical uptake is dependent on organ function, its blood supply and other factors which can affect uptake or excretion for example renal clearance (Gemmell et al 2005, Hartman N 2006) Clinical Issue A test we commonly perform looks at the left ventricle of the heart; this test is called a Multi Gated Acquisition (MUGA) and is an absolute measure of left ventricle ejection fraction (LVEF) (Links JM, Becker LC, Shindledecker JG, Guzman P, Burow RD, Nikoloff EL, Alderson PO, Wagner HN 1982) The value obtained from these tests plays a vital role in patient management, for example if the value falls below a threshold the patient may not be able to continue with their chemotherapy treatment (National Institute for Health and Clinical Excellence 2006) Left ventricle ejection can be calculated by other numerous other means such as trans-thoracic echo, planar echo, two plane echo and MRI (Nelson 1979, Sutton 1997 and Gunning 1997) However as I stated earlier MUGA’s are the preferred method for LVEF calculations as they are safe, simple and not based on assumptions of ventricular geometry (Slutsky R, Karliner J, Ricci D, Kaiser R, Pfisterer M, Gordon D, Peterson K and Ashburn W 1979) Within our department we can also calculate LVEF values from another test which primarily is designed to look at the perfusion of the myocardium under duress and at rest (Mochizuki 1997, Gunning 1997, Germano & Daniel S Berman 1999) Within our department this is performed using a compound called Technetium 99m Sestamibi We would administer the compound whilst the patient is undergoing pharmacological stressing according to the standard operating procedures and then image the patient using single photon emission tomography (SPECT) If the patient is placed on a lead ECG machine the data collected -2- Student Number: 109793 from this SPECT acquisition can be “gated”, allowing the size and shape of the heart muscle to be visualised at the peak of the systolic and diastolic phases (Germano, Berman 1999) Once the data is collected a processing package called cedars provides readouts of estimated LVEF (Germano et al 1999) Many papers have been written on calculating the ejection fraction from MIBI SPECT studies including Mochizuki et al (1997), Gunning et al (1997) and Germano et al (1999), and there is an argument that this value is more reliable then one obtained from MUGA scans (Guido Germano et al 1999) The argument for this is based on the acquisition parameters, specifically that the image is acquired from all angles This is important when one needs to consider any attenuating material that may be present on the patient or inside their body If one was to perform a MUGA study and there was say an internal breast implant then that would attenuate the gamma rays emitted by the radio labelled blood, thus affecting the result This paper does not address MUGA scans, instead it compares first pass radio nuclide angiography and contrast left ventriculography to Tc99 Tetrofosmin gated SPECT acquisitions Concept Analysis A concept analysis is performed by a researcher to provide a clearer understanding of the topic in hand, it has been described as “a process of strategic examination of the scientific literature that results in an integrated perspective of the state of the science, or what is known about the concept” (Hupcey, Penrod 2005) and it involves examining sources of information on a subject and is essential when considering a topic for research According to Morse JM, Hupcey JE, Mitcham C and Lenz ER (1996) there are four major methods to concept analysis; Wilson-derived, qualitative and quantitative methods and critical analysis of the literature Morse et al state (1996) that the method used for concept analysis depends on the purpose of the analysis -3- Student Number: 109793 A common method used to help with the concept analysis is the use of mind maps, these are diagrams where the research topic is placed in the centre and variables that are affected by or affect the research placed around the outside Literature search “A literature search involves using a range of resources to find books, journals, databases and web sites that are concerned with the subject you are researching” Kingston University (2006) According to Younger (2004) the best way to a literature search is to start by making a plan of what you are looking for and how you plan on getting it McManus et al (1998) state that the gold standard for a literature search is to search through journals by hand and point out that electronic databases such as Medline may identify only half of what could be found by hand (McManus, Wilson, Delaney, Fitzmaurice, Hyde, Tobias, Jowett and Hobbs 1998) This plan needs to be used in conjunction with a tight recording process so it can be seen which resources were used, which terms were searched for and which of these was most successful (Younger 2004) To get my paper of choice I had to perform a number of searches, the first search was as I expected unfruitful, I searched ProQuest for the word ‘Muga’ in the abstract this provided only 69 results which covered a very broad spectrum of topics Younger (2004) specifies that to get more results one can use a colloquial or alternative term, so I then decided that I would restart the search and use different keywords, this included using additional terms such as Left ventricle I first searched within ProQuest for ‘left ventricle’ and got 2204 hits, to narrow this down I then included, using the ‘and’ operator, the term ‘ejection’ this brought the total results down to 174 and when the term ‘ejection’ was changed to ‘ejection fraction’ the same number of results was returned -4- Student Number: 109793 To narrow these results down once again I chose to add the search term ‘measurement’ this should then bring the selection of papers to only ones which cover the measurement of the left ventricle This new search method left me with 32 results of which I then chose 8, see figure Fig After selecting these papers I read the abstracts and decided that none of them were within my area of practice and also suitable for critiquing I looked at the paper entitled ‘A realistic 3D gated cardiac phantom for quality control of gated myocardial perfusion SPET: the Amsterdam gated (AGATE) cardiac phantom’ and found references to papers which could be used as evidence for practice Within these references was a paper entitled “Left Ventricular Volumes and Ejection Fraction Calculated from Quantitative Electrocardiographic-gated 99mTCtetrofosmin Myocardial SPECT” To access this paper I used Athens online, I first selected the page entitle ‘My Journals’ which shows all of the journals that I can access Here I found that I could follow a link to ProQuest and access the full text articles from the desired journal from 1996 onwards I then had to find -5- Student Number: 109793 my paper within the journal, I found that when I had been linked to ProQuest it had given me a publication identification number so I proceeded to search for the following “(left ventricle) AND PMID (39290)” this gave me 19 results and included the paper I was looking for I read the abstract of this paper and decided this would be a good paper to choose as it is an experimental paper which addresses LVEF calculations from SPECT imaging Thus my chosen paper is: “Left Ventricular Volumes and Ejection Fraction Calculated from Quantitative Electrocardiographic-gated 99mTC-tetrofosmin Myocardial SPECT” -6- Student Number: 109793 Critical Appraisal of Research Critical appraisal of research is performed to analyse the evidence for flaws and problems within the research process before implementing the results into practice It is used to systematically examining research evidence to assess its validity, results and relevance before using it to inform a decision (Alison Hill 2001) Hill (2001) also states that “Critical appraisal allows us to make sense of research evidence and thus begins to close the gap between research and practice.” They argue that randomised controlled trials can minimise bias as they are the top of the hierarchy of evidence I located a framework for critical appraisal of literature It is from a government website and the questions for critical appraisal are derived from many authors including Parahoo Crombie Couchman and Cormack (NHS Executive 1996) -7- Student Number: 109793 The title The title states the focus is on LVEF calculated from ECG gated Tetrofosmin myocardial SPECT What the title does not say is that it is validating the previous technique neither is there any indication of the research approach or methods used in this paper -8- Student Number: 109793 The reason for the study The study is outlined in the introduction to the paper; the author outlines the history of the technique in question and then provides weak justification for the study The author argues that the technique has been tested and provides references, the author then states that “most previous reports” either were subjective or used a partially automatic technique Importantly the author does not provide any examples of this The overall outline provided by the introduction is that the authors have performed a study on a tested technique where previous testing may have been subjective There is no hypothesis but the author states that the previous studies had a high correlation between modalities, he does not indicate they are expecting similar results or otherwise If a hypothesis was included then for it to be complete it would need to mention the variables, the population and any predicted relationship between variables (parahoo) A null hypothesis for this study would there fore be along the lines of: “There will be no variation in the measured LVEF calculated through three means in Japanese patients suffering from coronary heart disease who have normal sinus rhythm and no bundle branch block.” The final choice of the research will according to parahoo () be based on numerous factors including the lack of research on the subject and the researchers pre existing knowledge, skills and interests -9- Student Number: 109793 The review of the literature The introduction cites pieces of literature these are all dated within four years previous to this study The author states that recent studies have shown it is possible to calculate LVEF from ECG gated SPECT and gives two examples According to Parahoo (XXX), the literature search can be used to narrow down the research scope by providing more information on what has already been done and thus what now needs to be done - 10 - Student Number: 109793 The sample The sample is described as 21 subjects undergoing three diagnostic tests within a fixed time frame The author identifies that all patients had a normal sinus rhythm (gating purposes) without bundle block The author has taken into account other heard conditions and outlined them, there was only one patient who had normal cardioangiograms and normal perfusion images on Tetrofosmin SPECT Sixteen subjects had coronary heart disease; one could argue this is the target group as the perfusion SPECT images are primarily looking for reversible ischemia where a physiological exercise test is not possible The research was done in Japan which is important when you consider the average bmi One factor which effects Tc99m Tetrofosmin imaging is adipose tissue; this will attenuate gamma rays as well as increasing the camera to target distance This will dramatically affect the quality and reliability of the images (Gemmell H, Murray A, Sharp P 2005) Statistics taken from OECD ( ) show that 2.9% of Japanese people are considered obese body mass index >30 where as 20% of the UK population are considered obese Parahoo states that the degree of fit between the sample and population is very important, in this paper the author has not specified a population; however by looking at the sample we can extrapolate that the population is in fact “Japanese patients suffering from coronary heart disease who have normal sinus rhythm and no bundle branch block” There is no mention of the method of sampling used however the author acknowledges it is a small sample A study was performed in 1990 by Polit and Sherman which showed that 62 articles had insufficient power to detect real effects due to small sample sizes Polit and - 11 - Student Number: 109793 Hungler (1995) also argue that the bigger the sample size the more representative it will be of the population Data collection the author has performed a piece of research using a correlation method The Correlation method is a non experimental, descriptive method as variables are not directly manipulated According to MCIL (2001) correlation is really more of a mathematical technique for summarizing data in that it is designed to analyse the degree and direction of relationship between two or more variables In this case the relationship between LVEF calculated from three modalities The strength in this method is that it can be used to determine if there is a relationship between two variables without having to directly manipulate those variables (MCIL 2001) The author has provided operational definitions for the three procedures which were performed for this paper; this includes a brief outline of processing methods Immediately the first point of note is that first pass radionuclide angiography methodology could be improved (Ref lao left ventricle separation) The author states that the data is interpreted by independent observers but does not states how many, we know there are at least two observers as the author has performed interoperator reliability According to Bera (2003) it is good practice to provide a clear explanation of the methods used with regards to the aim of the study and also indicate the pro’s can cons of such an approach in the paper Our authors have not done this - 12 - Student Number: 109793 Data Analysis The paper is a quantitative research study, the data collected is continuous data, it has a true zero point and thus it is ratio data (Dr R Ouyang 199?, UWE Bristol 2006) The author chooses to analyze this data using the following techniques: Linear Regression Determination of SEE Bland Altman analysis Paired student t-test Linear regression is used to analyse the relationship between two variables, in the case of this paper the linear regression is shown in a series of graphs comparing the results of two tests - 13 - Student Number: 109793 - 14 - Student Number: 109793 Stats online : http://www.statsoft.com/textbook/stathome.html Useful links : http://www.richard.ingram.nhspeople.net/student/critintro.htm References: Alison Hill (2001) What is critical appraisal Hayward Medical Communications Available: http://www.jr2.ox.ac.uk/bandolier/painres/download/whatis/What_is_critical_appraisal.pdf [Created 2001; Accessed 12/12/2007] Bera (2003) Good practice in educational research writing Available: http://www.bera.ac.uk/publications/pdfs/GOODPR1.PDF [Created 2003; Accessed 12/12/07] - 15 - Student Number: 109793 Gemmell H, Murray A, Sharp P (2005) Practical Nuclear Medicine 3rd Edition Singapore Springer-Verlay London Limited Germano, Berman (1999) On the accuracy and reproducibility of quantitative gated myocardial perfusion SPECT The Journal of Nuclear Medicine New York: May 1999 Vol 40, Iss 5; p 810 Gunning, Anagnostopoulos, Davies, Forbat (1997) Gated technetium-99m-tetrofosmin SPECT and cine MRI to assess left ventricular contraction The Journal of Nuclear Medicine New York: Mar 1997 Vol 38, Iss 3; p 438 Hartman N (2006) Radiopharmacy – Problems Encountered With the Products Hospital Pharmacist September; Volume 12 : Hupcey JE, Penrod J (2005) Concept analysis: examining the state of the science Research and theory for nursing practice 2005 summer; 19(2):197-20 Kingston University (2006) How to a literature search Available at: http://www.kingston.ac.uk/library/literatsearch.htm [Last modified 29-11-2006; Accessed 12/12/07] Links JM, Becker LC, Shindledecker JG, Guzman P, Burow RD, Nikoloff EL, Alderson PO, Wagner HN (1982), Measurement of absolute left ventricular volume from gated blood pool studies Circulation, [online] 65 (82-91), available at: http://circ.ahajournals.org [Accessed: 15/10/2007] - 16 - Student Number: 109793 McManus, Wilson, Delaney, Fitzmaurice, Hyde, Tobias, Jowett and Hobbs (1998), Review of Usefulness of contacting other experts when conducting a literature search BMJ, [Online] Available at: http://www.bmj.com/cgi/content/short/317/7172/1562 [Accessed: 19/11/2007] Mochizuki, Murase, Tanaka, Kondoh (1997) Assessment of left ventricular volume using ECG-gated SPECT with technetium-99m-MIBI and technetium-99m-tetrofosmin The Journal of Nuclear Medicine New York: Jan 1997 Vol 38, Iss 1; p 53 Morse JM, Hupcey JE, Mitcham C and Lenz ER (1996) Concept analysis in nursing research: a critical appraisal Scholary enquiry for nursing practice 1996 Fall; 10(3):253-77 Polit and Sherman (1990) Statistical power in nursing research Nursing research, 39(6) 365369 National Institute for Health and Clinical Excellence 2006 Press Release: Nice issues final guidance on trastuzumab (Herceptin) for early breast cancer [Online] London: NICE Available: http://www.nice.org.uk [Accessed 15/10/07] NHS Executive (1996) Achieving Effective Practice A Clinical Effectiveness and research information pack for nurses, midwives and health visitors Available: http://www.dh.gov.uk/assetroot/0404246204042462.pdf [Created 1996; Accessed 6/11/07] Ouyang (199?) Basic Concepts of Quantitative Research Available: http://ksumail.kennesaw.edu/~rouyang/ED-research/results.htm (created 199? ; Accessed 11/12/07) Schepis, Gaemperli, Koepfli, Valenta (2006) Comparison of 64-Slice CT with Gated SPECT for Evaluation of Left Ventricular Function The Journal of Nuclear Medicine New York: Aug 2006 Vol 47, Iss 8; p 1288 - 17 - Student Number: 109793 Slutsky R, Karliner J, Ricci D, Kaiser R, Pfisterer M, Gordon D, Peterson K and Ashburn W (1979), Left ventricular volumes by gated equilibrium radionuclide angiography: a new method Circulation, [online] 60 (556-564), Available at: http://circ.ahajournals.org [Accessed: 15/10/2007] Younger P (2004) Using the internet to conduct a literature search Nursing Standard 19, 6, 45-51 UWE BRISTOL (2006) Data Analysis – quantitative analysis - Types of Data Available: http://hsc.uwe.ac.uk/dataanalysis/quantIssuesTypes.asp (last modified 13/07/2006; Accessed 11/12/07) Sheffield University (????) Critical appraisal – Introduction Available: http://www.shef.ac.uk/scharr/ir/units/critapp/introduction.htm (created ????; Accessed 13/12/07) concept analysis http://www.journalofadvancednursing.com/default.asp?file=guidesummary google books concept analysis http://books.google.com/books? id=ZNjfFYcOOT0C&pg=PA55&lpg=PA55&dq=%22concept+analysis%22+formal&source=web&ots=qYc1nXNMZE&sig=JWxN85awHbdSgwyyScH9rbtIbsk Maricopa Center for Learning and Instruction(MCLI)(2001) Research Methods Available http://www.mcli.dist.maricopa.edu/proj/res_meth/rmvl/index.html [last modified 26/Oct/01; Accessed16/12/07] polit and hungler - 18 - Student Number: 109793 Parahoo oecd - 19 - ... of what you are looking for and how you plan on getting it McManus et al (1998) state that the gold standard for a literature search is to search through journals by hand and point out that electronic... research is performed to analyse the evidence for flaws and problems within the research process before implementing the results into practice It is used to systematically examining research evidence. .. proceeded to search for the following “(left ventricle) AND PMID (39290)” this gave me 19 results and included the paper I was looking for I read the abstract of this paper and decided this would