Heart rate variability (HRV) is a reliable reflection of the many physiological factors modulating the normal rhythm of the heart. In fact, they provide a powerful means of observing the interplay between the sympathetic and parasympathetic nervous systems. It shows that the structure generating the signal is not only simply linear, but also involves nonlinear contributions. Heart rate (HR) is a nonstationary signal; its variation may contain indicators of current disease, or warnings about impending cardiac diseases. The indicators may be present at all times or may occur at random-during certain intervals of the day. It is strenuous and time consuming to study and pinpoint abnormalities in voluminous data collected over several hours. Hence, HR variation analysis (instantaneous HR against time axis) has become a popular noninvasive tool for assessing the activities of the autonomic nervous system. Computer based analytical tools for in-depth study of data over daylong intervals can be very useful in diagnostics. Therefore, the HRV signal parameters, extracted and analyzed using computers, are highly useful in diagnostics. In this paper, we have discussed the various applications of HRV and different linear, frequency domain, wavelet domain, nonlinear techniques used for the analysis of the HRV.

Heart rate variability: a review

Objectives: To describe techniques for retrieval and appraisal used by consumers when they search for health information on the internet. Design: Qualitative study using focus groups, naturalistic observation of consumers searching the world wide web in a usability laboratory, and in-depth interviews. Participants: A total of 21 users of the internet participated in three focus group sessions. 17 participants were given a series of health questions and observed in a usability laboratory setting while retrieving health information from the web; this was followed by in-depth interviews. Setting: Heidelberg, Germany. Results: Although their search technique was often suboptimal, internet users successfully found health information to answer questions in an average of 5 minutes 42 seconds (median 4 minutes 18 seconds) per question. Participants in focus groups said that when assessing the credibility of a website they primarily looked for the source, a professional design, a scientific or official touch, language, and ease of use. However, in the observational study, no participants checked any “about us” sections of websites, disclaimers, or disclosure statements. In the post-search interviews, it emerged that very few participants had noticed and remembered which websites they had retrieved information from. Conclusions: Further observational studies are needed to design and evaluate educational and technological innovations for guiding consumers to high quality health information on the web. What is already known on this topic Little is known about how consumers retrieve and assess the quality of health information on the internet Qualitative data are needed to design educational and technological innovations to guide consumers to high quality health information What this study adds Users of the internet explore only the first few links on general search engines when seeking health information Consumers say that when assessing the credibility of a site they primarily look for the source, a professional design, and a variety of other criteria In practice, internet users do not check the “about us” sections of websites, try to find out who authors or owners of the site are, or read disclaimers or disclosure statements Very few internet users later remember from which websites they retrieved information or who stood behind the sites

https://www.bmj.com/content/bmj/324/7337/573.full.pdf

How do consumers search for and appraise health information on the world wide web? Qualitative study using focus groups, usability tests, and in-depth interviews

Many doctors, patients, journalists, and politicians alike do not understand what health statistics mean or draw wrong conclusions without noticing. Collective statistical illiteracy refers to the widespread inability to understand the meaning of numbers. For instance, many citizens are unaware that higher survival rates with cancer screening do not imply longer life, or that the statement that mammography screening reduces the risk of dying from breast cancer by 25% in fact means that 1 less woman out of 1,000 will die of the disease. We provide evidence that statistical illiteracy (a) is common to patients, journalists, and physicians; (b) is created by nontransparent framing of information that is sometimes an unintentional result of lack of understanding but can also be a result of intentional efforts to manipulate or persuade people; and (c) can have serious consequences for health. The causes of statistical illiteracy should not be attributed to cognitive biases alone, but to the emotional nature of the doctor-patient relationship and conflicts of interest in the healthcare system. The classic doctor-patient relation is based on (the physician's) paternalism and (the patient's) trust in authority, which make statistical literacy seem unnecessary; so does the traditional combination of determinism (physicians who seek causes, not chances) and the illusion of certainty (patients who seek certainty when there is none). We show that information pamphlets, Web sites, leaflets distributed to doctors by the pharmaceutical industry, and even medical journals often report evidence in nontransparent forms that suggest big benefits of featured interventions and small harms. Without understanding the numbers involved, the public is susceptible to political and commercial manipulation of their anxieties and hopes, which undermines the goals of informed consent and shared decision making. What can be done? We discuss the importance of teaching statistical thinking and transparent representations in primary and secondary education as well as in medical school. Yet this requires familiarizing children early on with the concept of probability and teaching statistical literacy as the art of solving real-world problems rather than applying formulas to toy problems about coins and dice. A major precondition for statistical literacy is transparent risk communication. We recommend using frequency statements instead of single-event probabilities, absolute risks instead of relative risks, mortality rates instead of survival rates, and natural frequencies instead of conditional probabilities. Psychological research on transparent visual and numerical forms of risk communication, as well as training of physicians in their use, is called for. Statistical literacy is a necessary precondition for an educated citizenship in a technological democracy. Understanding risks and asking critical questions can also shape the emotional climate in a society so that hopes and anxieties are no longer as easily manipulated from outside and citizens can develop a better-informed and more relaxed attitude toward their health.

/pdf/helping-doctors-and-patients-make-sense-of-health-statistics-1pvokbc1l2.pdf

Helping Doctors and Patients Make Sense of Health Statistics

http://iase-web.org/documents/papers/icots8/ICOTS8_PL3_GIGERENZER.pdf

Helping doctors and patients make sense of health statistics: towards an evidence-based society

Reduced heart rate variability carries an adverse prognosis in patients who have survived an acute myocardial infarction This article reviews the physiology, technical problems of assessment, and clinical relevance of heart rate variability The sympathovagal influence and the clinical assessment of heart rate variability are discussed Methods measuring heart rate variability are classified into four groups, and the advantages and disadvantages of each group are described Concentration is on risk stratification of postmyocardial infarction patients The evidence suggests that heart rate variability is the single most important predictor of those patients who are at high risk of sudden death or serious ventricular arrhythmias

https://onlinelibrary.wiley.com/doi/pdf/10.1002/clc.4960130811

Heart rate variability

Connectionist models such as neural networks are alternatives to linear, parametric statistical methods. Neural networks are computer-based pattern recognition methods with loose similarities with the nervous system. Individual variables of the network, usually called 'neurones', can receive inhibitory and excitatory inputs from other neurones. The networks can define relationships among input data that are not apparent when using other approaches, and they can use these relationships to improve accuracy. Thus, neural nets have substantial power to recognize patterns even in complex datasets. Neural network methodology has outperformed classical statistical methods in cases where the input variables are interrelated. Because clinical measurements usually derive from multiple interrelated systems it is evident that neural networks might be more accurate than classical methods in multivariate analysis of clinical data. This paper reviews the use of neural networks in medical decision support. A short introduction to the basics of neural networks is given, and some practical issues in applying the networks are highlighted. The current use of neural networks in image analysis, signal processing and laboratory medicine is reviewed. It is concluded that neural networks have an important role in image analysis and in signal processing. However, further studies are needed to determine the value of neural networks in the analysis of laboratory data.

Artificial neural networks for decision support in clinical medicine.

Information and its handling and transmission form an essential part of health care and are reflected in professional standards. Automated information systems in health care—health informatics services—will improve these functions and bring new opportunities through the harnessing of modern information and communications technologies. Thus, computer support is now essential in many parts of medicine, the US Institute of Medicine has long espoused the value of computerised patient records,1 and many countries have developed strategies on this topic, and there are countless health related internet sites.

However, as new information and communication technologies in health bring new opportunities, they also bring new risks. Emphasis has rightly been placed on ensuring appropriate levels of confidentiality in electronic information systems—to the point that the highly exacting requirements being demanded by independent commentators and professional bodies2 are difficult to satisfy without jeopardising the functioning of core services 3 4 or the interests of the most vulnerable groups.5 In contrast, much less thought has been given so far to ensuring the appropriateness of the design and integrity of functioning of health informatics services.

#### Summary points

Like drugs 40 years ago, products in health informatics are unregulated with regard to safety and efficacy

A European project has now recommended ways of accrediting healthcare related software, telemedicine, and internet sites

A scheme like CE marking of electrical goods is recommended for software, national regulatory bodies should be identified for telemedicine, and a European certification of integrity scheme developed for websites

If informatics systems are increasingly essential in the delivery of health care then their integrity and quality must be of equal importance, but this has been scarcely recognised to date. In 1963 the then UK secretary of state for health stated to the House of Commons: “The House and the public suddenly …

https://www.bmj.com/content/bmj/323/7312/552.full.pdf

Verifying quality and safety in health informatics services.

We compared the predictive value of determining group II phospholipase A2 (PLA2) in serum for diagnosing acute appendicitis with the predictive values of white blood cell count (WBC) and measurement of C-reactive protein (CRP). In this prospective study, we included 186 patients who were undergoing appendectomy after clinical diagnoses of acute appendicitis. The performance of each test was measured by receiver-operating characteristic curves. WBC was the test of choice in diagnosing uncomplicated acute appendicitis. However, in contrast to CRP and PLA2, which increased in patients with protracted inflammation, there was not a concomitant increase in WBC. Therefore, especially CRP, but also PLA2, were better indicators of appendiceal perforation or abscess formation than was WBC. Increased WBC, CRP, and PLA2 values did not unequivocally corroborate the clinical suspicion of appendicitis, but if all three values were within normal limits, acute appendicitis could be excluded with a 100% predictive value. PLA2 values showed a highly significant correlation with CRP but not with WBC values, which supports the view that PLA2 represents an acute-phase reactant.

Phospholipase A2, C-reactive protein, and white blood cell count in the diagnosis of acute appendicitis.

Serum Phospholipase A2 in Patients with Multiple Organ Failure

Objective: Drug interactions may lead to life-threatening injuries. More often, however, they lead to slow recovery, induce slight symptoms or result only in potential injury. Therefore, clinicians are not always aware of using potentially interacting drug combinations. An on-line alarming system of potential drug interactions was developed in Turku University Central Hospital. In the present study, we utilised the system to find out the incidence and nature of potential drug interactions occurring in a representative hospital patient population. Methods: Computerised anatomical therapeutic chemical (ATC)-coded patient medication data of 2547 patients, treated in two internal medicine wards, were combined with an ATC-coded rule base of drug interactions. All potential drug interactions in the study population were searched for. Results: A total of 326 potentially serious drug interactions were detected in the study population. The number of patients in this group was 173, i.e. 6.8% of all patients had one or several drug combinations which might have led to serious clinical consequences. Concomitant use of calcium and fluoroquinolones (decreased absorption) was the most common mistake (66 prescriptions). Conclusions: Potentially inappropriate drug combinations seem to occur frequently. Structured and coded medication data can be utilised efficiently to detect potential drug interactions in hospital. Computerised on-line monitoring and automatic alarming of potentially hazardous drug combinations might help clinicians to prescribe more safely, but further development of the system is needed to avoid unnecessary alarms.

Jari Forsström

Papers

Artificial neural networks for decision support in clinical medicine.

Verifying quality and safety in health informatics services.

Phospholipase A2, C-reactive protein, and white blood cell count in the diagnosis of acute appendicitis.

Serum Phospholipase A2 in Patients with Multiple Organ Failure

A medication database--a tool for detecting drug interactions in hospital.