By Z. Hjalte. Berkeley College. 2018.

Assessment of the possibility to classify patients according to cholesterol guideline screening criteria using routinely recorded electronic patient record data buy cialis extra dosage 40 mg otc. Successful introduction of Tallman letters to reduce medication selection errors in a hospital network purchase cialis extra dosage 50 mg visa. Improving anticoagulation management with a multidisciplinary anticoagulation team discount cialis extra dosage 100mg otc. Target controlled infusion of propofol for induction and maintenance of anaesthesia using the paedfusor: an open pilot study. Development and implementation of a pharmacy based, automatic dose standardization program for pediatrics. Selective chemoprophylaxis guided by multifactorial analysis in superficial bladder cancer. Intensive treatment with methotrexate in early rheumatoid arthritis: aiming for remission. Implementation of a computer assisted treatment planning and outcome evaluation system in a forensic psychiatric hospital. Failure to recognize loss of incoming data in an anesthesia record-keeping system may have increased medical liability. Discrepancies in medication entries between anesthetic and pharmacy records using electronic databases. Disease management for heart failure patients: role of wireless technologies for telemedicine. Effects of a pharmacist-to-dose computerized request on promptness of antimicrobial therapy. Modelling treatment effects in a clinical Bayesian network using Boolean threshold functions. Implementation and promotion of a computerized provider order entry program at a Department of Veterans Affairs medical center. Engineering Intelligent Systems for Electrical Engineering and Communications 2006;14(3):137-45. Quality of prescribing for the elderly in Croatia- computerized pharmacy data can be used to screen for potentially inappropriate prescribing. Evaluation of hydroxyurea prescribing in a large academic teaching hospital affiliated with a major cancer center. Use and impact of an automated telephone outreach system for asthma in a managed care setting. Effect of a novel birth intervention and reminder-recall on on-time immunization compliance in high-risk children. An aminoglycoside monitoring service in a community hospital using a microcomputer. Automation in pharmacy: two institutions’ experiences with novel distribution systems. Effect of intervention through a pharmaceutical care program on patient adherence with prescribed once-daily atorvastatin. Hospital information management system: an evolutionary knowledge management perspective. Pharmaceutical counselling of drug switches at the interface between primary and tertiary care. Participatory design of a text message scheduling system to support young people with diabetes. Improving patient safety and quality: what are the challenges and gaps in introducing an integrated electronic adverse incident and recording system within health care industry? Development of a clinical pharmacy automatic medicine dispensing and prescription information processing system. Prevention of pediatric medication errors by hospital pharmacists and the potential benefit of computerized physician order entry. Yakugaku Zasshi - Journal of the Pharmaceutical Society of Japan 2008;128(1):123-7. Active computerized pharmacovigilance using natural language processing, statistics, and electronic health records: a feasibility study. The use of a decision support software in pharmacy computer system to proactively prevent adverse drug events. Information technologies relevant to pharmacy practice in hospitals: Results of a statewide survey. Understanding caseload and practice through analysis of therapeutic state transitions. Utilising practice management system data for quality improvement in use of blood pressure lowering medications in general practice.

The primary goal in breast evaluation is to decide if further evaluation is needed based on initial findings proven 50mg cialis extra dosage. Normal physiologic variations related to hormonal cycling or benign breast conditions require patient education and reassurance cialis extra dosage 100 mg visa. Findings that are clearly benign may require periodic reexamination best cialis extra dosage 40 mg, but they may not require any further evaluation or treatment. Treatment options often are complex and involve physicians from mul- tiple disciplines. The surgeon also should be prepared to act as the coordinator of initial and follow-up care. The evaluation and management of patients with breast complaints and breast cancer are aided by a large body of evidence that has been derived from well-designed clinical trials conducted over the past few decades. While there are areas of legitimate disagreement among experts, there are many areas for which level I evidence is available to guide patient management. General Evaluation The two most common breast complaints are a palpable mass and an abnormal mammogram. These two entities, along with nipple dis- charge and a swollen, tender breast, represent almost all of the patient scenarios that a surgeon is likely to encounter (Table 19. The duration of the complaint as well as any fluctuation of the complaint with the monthly menstrual cycle are important to note. The surgeon should inquire about the presence of breast pain and the nature of any nipple discharge. Risk factors related to menstrual history and child- bearing are thought to represent the risk of exposure to endogenous estrogen. Although family history is important, one must remember that the majority of breast cancer patients do not have a family history. A general examination of the patient focused on the lungs, chest wall, and abdomen also must be performed. If available, several years of images should be compared side by side in order to appreciate any subtle changes over time. The surgeon should be familiar with various diagnostic interven- tions that can be performed in the office. Once the evaluation is completed, most patients can be classified as having findings that are clearly benign, probably benign, or suspi- cious. Patients with findings that are probably benign should be followed with a repeat clinical examination in several months. The patient should not leave the office without making a specific follow-up appointment. The surgeon must be expert in the various tech- niques available for breast biopsy (Table 19. The case scenarios presented at the start of this chapter and discussed in the text that follows illustrate the evaluation and management of patients with common breast complaints. In addition, diagnostic tech- niques, the treatment of breast cancer, breast screening, and the evalu- ation of “high-risk” women are discussed. Palpable Breast Mass in a Younger Woman (Case 1) The patient in Case 1 has a finding that is probably benign. The primary differential is to deter- mine if this lesion is a cyst or if it is a solid mass. Core needle biopsy Image-guided core biopsy (stereotactic or ultrasound guided) Excisional biopsy Wire localized excisional biopsy Incisional biopsy (rarely used) 19. Other benign possibilities include juvenile fibroade- nomas, hamartomas, lipomas, and fat necrosis. The possibility that this is a phyllodes tumor and the remote possibility that this repre- sents breast cancer both must be considered. Fine-needle aspiration of the mass with a 23-gauge needle may result in the removal of cyst fluid, with resolution of the mass. If classic cyst fluid without any gross blood is obtained, it may be discarded, pro- vided that the mass resolves completely. A persistent mass after aspiration suggests a solid lesion, and the aspirated fluid should be sent for analysis as well. If no fluid is obtained, the needle may be passed through the lesion several times, and the resulting cellular material should be sent for cytologic evaluation. In many multi- disciplinary breast centers, on-site cytologic evaluation is available to assess adequacy of the sample and provide a quick diagnosis. The other alternative for this patient is ultrasound examination of the affected breast. The finding of a simple cyst with a smooth wall, no cystic debris, and good through transmission of ultrasound establishes the diagnosis of a simple cyst. If desired and if the cyst is tender or enlarges in the future, aspiration then can be performed. The finding of septations, mural nodules, or intracystic debris characterizes the cyst as a complex cyst. The finding of a smooth, homogeneous mass consistent with a fibroadenoma may be managed in several ways.

Additional points about some of these amino acids include: • Serine and threonine are sites for O-linked glycosylation of proteins cheap 60 mg cialis extra dosage overnight delivery, a posttransla- tional modification that should be associated with the Golgi apparatus order 40 mg cialis extra dosage overnight delivery. Asparagine is a site for N-linked glycosylation of proteins discount cialis extra dosage 100 mg on-line, a posttranslational modifi- cation that should be associated with the endoplasmic reticulum. Cysteine contains sulfur and can form disulfide bonds to stabilize the shape (tertiary structure) of proteins. He was taken to the hospital, where he was found to have mild anemia, splenomegaly, and rod-shaped crystals in the erythrocytes. To validate the diagnosis, a small aliquot of his blood was subjected to electrophoresis to determine the identity of the hemoglobin in his erythrocytes. After reviewing the data, the physician concluded that he did not have sickle cell anemia, but rather a sickle cell anemia-like hemoglobinopathy with the relatively common mutation of HbC. Episodes of vaso-occlusive pain lasting approximately 1 week are a frequent problem. A widely used method to analyze hemoglobins found in various hemoglobinopathies is electrophoresis at pH 8. In sickle cell anemia, there is a substitution of valine for glutamate at position 6 in Hb, mean- ing that the HbS will have one less negative charge overall compared with HbA. In HbC, there is a substitution of lysine for glutamate at position 6, meaning that HbC will have two additional positive charges compared with HbA. These three hemoglobins can be resolved by electrophoresis, as shown in the figure. Protein breakdown occurs generally in two cellular locations: • Lysosomal proteases digest endocytosed proteins. These amino acids can be derived from digesting dietary protein and absorbing their constituent amino acids or, alternatively, by synthesizing them de novo. The 10 amino acids listed in Table 1-8-1 cannot be synthesized in humans and therefore must be provided from dietary sources. Essential Amino Acids Arginine" Methionine Histidine Phenylalanine Isoleucine Threonine Leucine Tryptophan Lysine Valine "Essential only during periods of positive nitrogen balance. Nitrogen Balance Nitrogen balance is the (normal) condition in which the amount of nitrogen incorporated into the body each day exactly equals the amount excreted, Negative nitrogen balance occurs when nitrogen loss exceeds incorporation and is associated with: Note • Protein malnutrition (kwashiorkor) • A dietary deficiency of even one essential amino acid Do not confuse kwashiorkor Starvation with marasmus, which is a • Uncontrolled diabetes chronic deficiency of calories. Patients with marasmus do Infection not present with edema as Positive nitrogen balance occurs when the amount of nitrogen incorporated exceeds the patients do with kwashiorkor. Comparison of Energy and Rate Energy(~G) Rate (v) Not affected by enzymes Increased by enzymes ~G <0, thermodynamically Decrease energy of activation, ~G:j: spontaneous (energy released, often irreversible) ~G >0, thermodynamically nonspontaneous (energy required) ~G == 0, reaction at equilibrium (freely reversible) ~Go == energy involved under standardized conditions The rate of the reaction is determined by the energy of activation (~G:j:), which is the energy required to initiate the reaction. Enzymes lower the energy of activation for a reaction; they do not affect the value of ~G or the equilibrium constant for the reaction, Keq• Enzyme Uncatalyzed Catalyzed ~ >. In the cell, this can be accomplished by inducing the expression of the gene encoding the enzyme. Km is the substrate m concentration required to produce-half the maximum velocity. Under certain conditions, Km is a measure of the affmity of the enzyme for its substrate. When comparing two enzymes, the one with the higher K has a lower affinity for its substrate. The Km value is an intrinsic m property of the enzyme-substrate system and cannot be altered by changing [5] or [E]. When the relationship between [5] and V is determined in the presence of constant enzyme, many enzymes yield the graph shown in Figure 1-8-4, a hyperbola. Michaelis-Menten Plot lineweaver-Burk Equation The Lineweaver-Burk equation is a reciprocal form of the Michaelis-Menten equation. The actual data are represented by the portion of the graph to the right of the y-axis, but the line is extrapolated into the left quadrant to determine its intercept with the x-axis. Lineweaver-Burk Plot Inhibitors and Activators Note Three important classes of inhibitors are shown in Table 1-8-3. Competitive inhibitors resemble Drugs That Competitively the substrate and compete for binding to the active site of the enzyme. Notice that on a Lineweaver-Burk graph, inhibitors always lie above the control on the an antineoplastic drug, right side of the y-axis. Lineweaver-Burk Plot of Competitive Inhibition of Noncompetitive Inhibition Cooperative Enzyme Kinetics ~! Cooperative m enzymes are sometimes referred to as allosteric enzymes because of the shape changes that are compared with methanol. Cooperative Kinetics Transport Kinetics The K and Vmax parameters that apply to enzymes are also applicable to transporters m in membranes. The kinetics of transport can be derived from the Michaelis-Menten and Lineweaver-Burk equations, where Km refers to the solute concentration at which the trans- porter is functioning at half its maximum activity. Protein turnover and nitrogen balance: • Essential amino acids: phe, val, trp, thr, ile, met, his, Iys, leu, arg (only during positive N-balance) • Negative: nitrogen lost> nitrogen gained (illness, protein malnutrition, deficiency of an essential amino acid) • Positive: nitrogen lost < nitrogen gained (growth, pregnancy, convalescence) Enzyme kinetics: • Enzymes do not affect energy of reaction, ~G. The peptide ala-arg-his-gly-glu is treated with peptidases to release all of the amino acids.

However cialis extra dosage 200mg generic, evaluations of health care delivery buy cialis extra dosage 40 mg low cost, such as comparisons of effectiveness of treatment or prevention methods (e order cialis extra dosage 50mg amex. Furthermore, the more rigorous and transferable research conducted tends to show no or limited effect on patient-important clinical outcomes. Research to date has concentrated on measurement of process changes and descriptive and pilot studies. In addition, some studies based on stronger methods have failed on issues such as adequate concealment of allocation and blinding, poor understanding of some methods, lack of adjustment of groups, and statistical challenges. Researchers should also be encouraged to consider the generalizability or transferability of their results for all of their projects. This has made identification of studies, data abstraction, synthesis of evidence, and presentation of findings challenging. Many study reports did not include important information that would have made this report stronger. Interventions most frequently targeted prescribing and monitoring stages of the medication use process. Physicians who provided care in the hospital and ambulatory care settings were most likely to be the target of the intervention. Workflow, communication, interaction with peers and time considerations were found to be improved less often. This was particularly true when patient-centered principles were employed, such as providing patients with reminders and decision support recommendations about their current health status. Differences in study outcomes for similar qualitative studies across settings were not apparent, suggesting that findings from qualitative studies could be transferrable across settings. From qualitative studies, system design including workflow changes, challenges with the system interface and new communication processes demonstrated that without adequate attention to system changes, the new kinds of medical errors with potential detrimental impact to patient safety could occur. Cost analyses can provide useful information on ‘upfront’ costs compared with ‘downstream’ cost avoidance if they explicitly measure all direct health care costs (e. The full enumeration of the total costs needs to be synthesized with the consequences or outcomes of the intervention (i. Adoption of newer technologies needs to be based on formal evaluation of whether the additional health benefit (effectiveness) is worth the additional cost. Unintended consequences, both positive and negative, were found across many of the studies as main endpoints, or were alluded to in others. A tracking system of major and clinically important unintended consequences would be useful for many audiences and should be considered by system developers and funding agencies. Clinicians, administrators, and likely patients and their families have different values and place varying importance on each. Both facilitators and barriers exist that impact movement to implementation of e-Prescribing and two-way communication designed to enhance and streamline prescription optimization. Although we tried to be thorough in our search methods, we feel that we did not capture all potential articles—a very difficult task in new and multidisciplinary areas of study. Further, we concentrated only on the main or major endpoints reported in studies with comparison groups and hypothesis testing. Given the heterogeneity in the literature, it was often difficult to discern main endpoints; where possible we determined main endpoints as those declared as such, or those that were the basis of power calculations (infrequently), or were stated to be main outcome measures in the abstract or objectives. In these cases we gave priority to outcomes related to medication management and clinically important patient outcomes. It has proven difficult to synthesize the evidence on such a range of technologies, implemented in a number of settings and used by various stakeholders. Each intervention is so complex that it is often difficult to tell which studies are assessing the same processes. For example, similar outcomes such as prescribing changes were measured as changes in daily doses; prescribing rates per hospital, per physician, per 1,000 patient days, etc. The number of orders and compliance rates were difficult to extract and synthesize. Our ability to draw conclusions is also reliant on the quality of the evidence we have found. Only a small minority of these studies focus on clinical outcomes—the endpoints that are most important to guide decisions by patients, providers and policymakers, about adopting these interventions. A large number of studies neglected to report the study dates 106 (see Evidence Tables in Appendix C). Although the absence of a contemporaneous comparable control group is a problem with all observational studies, the creation of control groups by comparing intervention patients to those that do not participate, or do not have a problem to those that do is fundamentally far more likely 18 to introduce major bias in the comparison (e. Many observational studies suffered from selecting an outcome that was distantly or only marginally related to the intervention. Moreover, in a substantial proportion of negative studies, minimal adoption was seen.

The substance to which the H2 atoms are transferred is called the hydrogen acceptor 50 mg cialis extra dosage sale. In anaerobic respira- tion generic cialis extra dosage 60 mg overnight delivery, the O2 that serves as the hydrogen acceptor is a component of an inor- ganic salt buy cialis extra dosage 50 mg with visa. The main difference between fermentation and respiration is the energy yield, which can be greater from respiration than from fermentation for a given nutrient substrate by as much as a factor of 10. Fermentation processes involving microorganisms are designated by the final product, e. The energy released by oxidation is stored as chemical energy in the form of a thioester (e. Anaerobic respiration is when the electrons are transferred to inorganically bound oxygen. Oxygen is activated in one of three ways: & Transfer of 4e– to O, resulting in two oxygen ions (2 O2–). The Physiology of Metabolism and Growth in Bacteria 163 Bacteria are categorized as the following according to their O2-related behavior: & Facultative anaerobes. These bacteria can oxidize nutrient substrates by means of both respiration and fermentation. Their metabolism is adapted to a low redox potential and vital enzymes are in- 3 hibited by O2. These bacteria oxidize nutrient substrates with- out using elemental oxygen although, unlike obligate anaerobes, theycan tol- erate it. The principle of the biochemical unity of life asserts that all life on earth is, in essence, the same. Thus, the catabolic intermediary metabolism of bacteria is, for the most part, equiva- lent towhat takes place in eukaryotic cells. The reader is referred to textbooks of general microbiology for exhaustive treatment of the pathways of inter- mediary bacterial metabolism. Anabolic Reactions It is not possible to go into all of the biosynthetic feats of bacteria here. Some bacteria are even capable of using aliphatic hydrocarbon compounds as an energy source. It is hoped that the metabolic capabilities of these bacteria will help control the effects of oil spills in surface water. Bacteria have also been enlisted in the fight against hunger: certain bacteria and fungi are cultivated on aliphatic hydrocarbon substrates, which supplycarbon and energy, then harvested and processed into a protein powder (single cell protein). Culturing of bacteria in nutrient mediums based on methanol is another approach being used to pro- duce biomass. One form such control activity takes is regulation of the activities of existing enzymes. Many enzymes are allosteric proteins that can be inhibited or activated by the final products of metabolic pathways. One highly economical type of regulation controls the synthesis of 3 enzymes at the genetic transcription or translation level (see the section on the molecular basis of bacterial genetics (p. Growth and Culturing of Bacteria Nutrients The term bacterial culture refers to proliferation of bacteria with a suitable nutrient substrate. Other necessities include sources of carbon and nitrogen for synthesis of specific bacterial compounds as well as minerals such as sul- fur, phosphorus, calcium, magnesium, and trace elements as enzyme activa- tors. Nutrient agar liquefies when heated to 1008C and does not return to the gel state until cooled to 458C. Selective mediums Contain inhibitor substances that allow only certain bacteria to proliferate. The Physiology of Metabolism and Growth in Bacteria 165 Growth and Cell Death Bacteria reproduce asexually by means of simple transverse binary fission. The time required for a reproduction cycle (G) is called the generation time (g) and can vary greatly from species to species. Fast-growing bacteria cultivated in vitro have a gen- eration time of 15–30 minutes. Obligate anaerobes grow much more slowly than aerobes; this is true in vitro as well. Of course the generation time also depends on the nutrient con- tent of the medium. The so-called normal growth curve for bacteria is obtained by inoculat- ing a nutrient broth with bacteria the metabolism of which is initially quies- cent, counting them at intervals and entering the results in a semilog coor- dinate system (Fig. The lag phase (A) is characterized by an increase in bacterial mass per unit of volume, but no increase in cell count. During this phase, the metabolism of the bacteria adapts to the conditions of the nutrient medium. In the following log (or exponential) phase (C), the cell count in- creases logarithmically up to about 109/ml. This is followed by growth decel- eration and transition to the stationary phase (E) due to exhaustion of the nutrients and the increasing concentration of toxic metabolites. The generation time can only be determined dur- ing phase C, either graphically or by determining the cell count (n) at two different times and applying the formula: t2 À t1 g ¼ : log2 n2 À log2 n1 Normal Growth Curve of a Bacterial Culture Fig.

Labile hemoglobin is formed initially when the aldehyde of glucose reacts with the N-terminal valine of the β globin chain cialis extra dosage 40 mg free shipping. This Shiff base is reversible but is converted to Hgb A1c by rearrangement to a ketoamine 50 mg cialis extra dosage overnight delivery. A fasting glucose of 126 or higher on two consecutive occasions indicates diabetes generic 40mg cialis extra dosage visa. A fasting glucose of 99 mg/dL is considered Peak Calibrated Retention Peak normal. May be used only to monitor persons with type 2 diabetes Chemistry/Correlate clinical and laboratory data/ Glycated hemoglobin/2 210 Chapter 5 | Clinical Chemistry 18. What is the recommended cutoff for the early Answers to Questions 18–21 detection of chronic kidney disease in diabetics using the test for microalbuminuria? The term microalbuminuria is defined as albumin excretion ≥ 30 mg/g creatinine Chemistry/Evaluate laboratory data to recognize health but ≤ 300 mg/g creatinine. The use of the albumin and disease states/Glucose/2 to creatinine ratio is preferred to measures of 19. In addition to measuring blood glucose, Hgb A1c, albumin excretory rate (μg/min) because the latter and microalbumin, which test should be done on is subject to error associated with timed specimen diabetic persons once per year? Estimated glomerular filtration rate have diabetes, it is not sensitive enough to manage Chemistry/Select method/Carbohydrates/2 glucose control on a daily basis, and has been 20. Which testing situation is appropriate for the use replaced by whole-blood glucose monitoring or of point-of-care whole-blood glucose methods? Screening for type 2 diabetes mellitus ketone test is a useful screening test for diabetic and B. Diagnosis of diabetes mellitus other forms of ketosis, the plasma β hydroxybutyrate C. Monitoring of blood glucose control in type 1 test should be used to identify and monitor ketosis in and type 2 diabetics diabetic persons. Monitoring diabetics for hyperglycemic Hgb A1c to identify poor control of blood glucose in episodes only the past 2–4 weeks, but has not been recommended for routine use in all diabetic patients. Which of the following is the reference method glucose monitors for establishing a diagnosis of for measuring serum glucose? Glucose dehydrogenase analytical variance is greater and accuracy less than for Chemistry/Select method/Carbohydrates/2 laboratory instruments. Whole blood glucose meters should be used by diabetics and caregivers to monitor glucose control and can detect both hyper- and hypoglycemic states that result from too little or too much insulin replacement. Therefore, postprandial monitoring with such a device is recommended for all persons who receive insulin therapy. Polarographic methods for glucose analysis are Answers to Questions 22–26 based upon which principle of measurement? As the dissolved O2 oxidized decreases, less is reduced at the cathode, resulting in a decrease in current proportional to glucose Chemistry/Apply principles of basic laboratory concentration. It is important that the H2O2 not procedures/Carbohydrates/2 breakdown to re-form O2. In addition to polarography, what other adding molybdate and iodide that react with electrochemical method can be used to H O, forming iodine and water, and by adding 2 2 measure glucose in plasma? Amperometry is impregnated into the membrane covering the Chemistry/Apply principles of basic laboratory electrode. Select the enzyme that is most specific for anode of the electrode, where it is oxidized to O2. D Glucose oxidase is the most specific enzyme reacting characteristics/Biochemical/1 with only β-D-glucose. Select the coupling enzyme used in the hexokinase is subject to positive and negative interference. C Although glucose oxidase is specific for β-D-glucose, the coupling (indicator) reaction is prone to negative interference from ascorbate, uric acid, acetoacetic acid, and other reducing agents. Which of the following is a potential source Answers to Questions 27–31 of error in the hexokinase method? Therefore, hemolyzed samples require a Chemistry/Apply knowledge to recognize sources of serum blank correction (subtraction of the reaction error/Carbohydrates/2 rate with hexokinase omitted from the reagent). Levels below 40 mg/dL occur in septic glucose is usually 50%–65% of the plasma glucose. Hyperglycorrhachia is caused by dehydration cases of subarachnoid hemorrhage, rheumatoid D. B The coupling step in the Trinder glucose oxidase processes/Cerebrospinal fluid/2 method uses peroxidase to catalyze the oxidation of a dye by H2O2. In peroxidase-coupled glucose methods, which 4-aminoantipyrine are coupled to phenol to form a reagent complexes with the chromogen? For glucose oxidase Chemistry/Apply knowledge of basic laboratory methods, the electrons derive from the oxidation of procedures/Carbohydrates/1 hydrogen peroxide. Other factors include binding of devices oxygen to hemoglobin and the slower diffusion of C. Te effect is variable and dependent on the glucose onto the solid phase—both of which occur enzyme/coenzyme system when the hematocrit is high.

In this approach different extraction order cialis extra dosage 100mg, clean-up purchase cialis extra dosage 50 mg overnight delivery, and detection techniques were assigned a certain number of selectivity indices buy 60 mg cialis extra dosage free shipping. According to this document, to obtain adequate identification power, confirmatory methods have to provide information on the chemical structure of the substance and thus only spectrometric detection techniques are considered to be sufficient, among which fluorescence detection (only for group B substances) and mass spectrometry, both in combination with chromatography. This approach is derived from the previously mentioned approach based on “selectivity indices”, but because selectivity was then predominantly considered a function of the measuring technique, the extraction and clean-up were not included. For the identification of group B substances, three identification points were considered adequate and for group A substances, this is four identification points [57,87]. The number of points earned for each mass spectrometric technique is presented in table 1. Another option is the monitoring of two precursor ions, each with one product ion, resulting in five identification points. In all cases a minimum of one ion ratio (relative ion abundance) must be determined and all determined ion ratios must comply with the criteria as presented in table 1. Even though the approaches are very similar, the criteria for accepting or rejecting a match differ significantly. This document states that “calibration certificates shall contain the measurement results including the measurement uncertainty”. Often, uncertainty is solely regarded as a parameter applicable to quantitative results. However, ‘uncertainty’ can be interpreted as a much broader concept which involves both the quantitative and the qualitative aspect. Definition: “Uncertainty (in statistics) ► noun, the estimated amount or percentage by which an observed or calculated value may differ from the true value. Furthermore, the document defines confirmatory methods as “a method that provides full or complementary information enabling the substance to be unequivocally identified (…)” [57]. To obtain a clear view on the implications of this statement, a brief discussion on the concept of confirmation versus identification is needed, which is discussed in more detail elsewhere [80,81,95,98]. In this thesis the term ‘confirmation’ presumes knowledge on the identity of the compound present, e. A positive confirmation indicates that the result is not against the presumptions made: the compound shows the same characteristics as the reference compound selected, but it does not exclude the possibility of the presence of another compound showing the same characteristics. Establish the truth or correctness of (something previously believed or suspected to)” [2] In contrast, in ‘identification’ no a priori presumption on the substance present is made and thus identification requires that all other substances are excluded, so that the reported substance is the only possible candidate [95]. Definition: “Identification ► noun, the action or process of identifying someone or something or the fact of being identified. When realising the indefinite number of substances that exist (also including substances not yet known to mankind), unequivocal identification is an impossible task [80] and therefore a degree of uncertainty of the qualitative result should be considered depending on the risks involved related to a false positive finding [81]. Selectivity The identification power and therefore the qualitative uncertainty of the confirmatory method is expressed in its selectivity. This term is often interchangeably used with ‘specificity’ [99], which is actually the ultimate of selectivity [100]. In case of a false positive result the presence of a certain substance is reported whereas this specific substance is not present. The power of discrimination between the substance present and closely related substances (isomers, metabolites, degradation products, endogenous substances, matrix constituents, etc. When one realises that non-compliant analytical results in food product analysis can have a huge effect on personal lives and society as well as on economy this becomes more than evident. In case the presence of a banned substance is reported whereas it is not truly present in the sample, farmers may be falsely accused of using banned carcinogenic antibiotics and go bankrupt after prosecution; certain branches may get a bad reputation and people may choose to avoid buying certain products; shipments of perfect quality food products might be destroyed, affecting the economy, international relations and food security. From this it is clear that, especially for confirmatory methods, selectivity is a very important parameter. This depends on the point of view taken: strict criteria result in an increased probability of false negative results whereas less strict criteria result in an increased possibility of obtaining a false positive result. Although all of the ion ratio criteria were established based on experts’ judgment, it is not unlikely that incorrect identification takes place. The influence of matrix constituents on the ion ratio was described and appointed as a possible cause of deviating ion abundances. In summary, maximum tolerance limits for ion ratio and retention time as established in several legal documents are very useful tools for the confirmation but not necessarily for the identification of compounds. However, some aspects that are not explicitly stated in the guidelines should be taken into account: - The selectivity of the whole procedure, including the sample preparation procedure. An alternative to the use of a priori established tolerance limits as indicated by the legal framework was presented by Van de Voet et al. The applicability of constructing a confidence interval for the ion ratio based on empirical data was demonstrated using a multi-variate approach. This approach was found very useful to replace a priori established tolerance limits, especially at very low concentration levels.