Reference values in analyses: what they are, what they mean

The introduction of new concepts often negatively affects the psychological state of the patient when he examines the analysis form and discovers on it, in addition to his indicators, columns of numbers labeled with the term: reference values in analyses. What it is and why it is indicated next to the individual indicators handed out begins to worry the patient even more than their own results. Sometimes a person is sure that these words mean something bad and falls into complete confusion. There is no reason to worry, and this design of forms is associated with a revision of medical terminology in the light of the latest scientific distinctions. Any doctor knows what reference values and approximate indicators mean in his medical field, but they are still provided on the analysis form for his convenience.

What is the reference interval in tests?

Content

Over the course of many years of research and practice, modern medicine has discovered that the concept of “norm”, more familiar to the ear of the average patient, does not correctly reflect the essence of statistical data. The norm is a conditional term under which the indicators of an individual cannot be adjusted. Conducted research shows that for many people the concept of normal differs from the conventionally derived term norm, so this designation was considered not entirely appropriate and correct.

Reference values, norm, are terms of the same semantic series, established on the basis of an average value. The reference interval is the discrepancy in the levels of certain components observed in people who were tested for statistical data. The results of the reference interval are determined by the difference in individual indicators, external and internal conditions of the organism, and its physiological characteristics.

How is it determined

To determine the reference interval, the limits of reference values are taken - the largest and smallest indicators included in the relative state of health. If the data obtained for an individual patient falls within the interval between the largest or smallest value, his body is in a state of relative health. To make sure that there is a disease in the body, if the data obtained during the analysis are not included in the reference interval, a repeat test is often prescribed. Indicators in individual studies may change in one direction or another, under the influence of various factors.

The reference interval on the analysis data is determined by conducting research on the target audience (for example, healthy middle-aged men, or people of both sexes who do not have diseases). The upper and lower thresholds are those small numbers (usually 50 people out of a thousand) with the highest and lowest scores. The remaining values will be between these limits. The reference interval takes as the norm the data obtained in 95% of cases.

Semantics

In semantics, “reference” is the relationship between nouns or pronouns and the objects that are named by them. Therefore, the word "John" refers to the person John. The word "it" refers to some previously specified object. That is? The object referred to is called the referent of the word. Sometimes a word denotes an object. The reverse relation, the relation from an object to a word, is called an example; the object illustrates what the word stands for. In parsing, if a word is related to a previous word, the previous word is called an antecedent.

Gottlob Frege argued that the reference cannot be interpreted as being identical in meaning: "Hesperus" (the ancient Greek name for the "evening star") and "Phosphorus" (the ancient Greek name for the "morning star") refer to Venus, but the astronomical fact is that " Hesperus" is "Phosphorus", that is, it is still the same object, even if the meanings of the words mentioned are known to us. This problem led Frege to distinguish between meaning and reference to a word. Some cases seem too complex to be classified within this framework. Adopting the concept of a secondary link may be necessary to fill the gap.

Qualitative and quantitative characteristics

A qualitative characteristic is simply indicated by the words positive or negative result shown by the analysis. Quantitative characteristics are used more often, and this is information for the doctor, who, based on the obtained figures, can determine how serious deviations in the patient’s condition there are, if they are compared with what is indicated on the form as reference values. Decoding the data is usually the responsibility of a specialized specialist who knows what changes the numbers indicate. For many diseases, there are certain components of the diagnostic search, which are identified in each person using laboratory tests. If a doctor needs an exact answer in numbers, he receives quantitative characteristics on a standard form.

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Semantics

Established normal limits

International reference indicators are accepted only for generally accepted values - hemoglobin, cholesterol or glucose, and each laboratory sets all others based on its own data. Each laboratory may specify different ranges, and this may even depend on the measurement system in which they are reported (eg µg/liter, or µmol/l). The reference value of the analysis means nothing more than the average statistical values of studies taken from healthy patients (the norm, but recorded more correctly, according to scientists).

Types of reference groups

There are other classifications besides dividing types of groups into referential and non-referential.

Reference groups can also be informational. They are composed of experts, opinion leaders and popular people who are trusted in society.

There are value groups, they include carriers of the standards of the social-normative system, which people are ready to imitate.

Utilitarian reference groups provide a person with various material and spiritual benefits.

There are also self-identification groups. A person conditionally enters into them and begins to follow their rules.

By degree of impact

According to the degree of impact on a person, types of groups are positive and negative:

positive ones have a good effect on a person, he adopts their values and attitudes (major makeup artists instill in their viewers good taste and the ability to understand cosmetics);
negative ones make a person stay away. They are associated with failure, low status in society, lack of privileges and recognition. Typically, negative reference groups include people without a fixed place of residence, those associated with the criminal world, and the unemployed.

By relationships in the group

Relationships in the reference group can also be different:

formal relations in the reference group are formalized and confirmed by documents. The structure of relationships is special, multi-stage, subject to certain rules (military personnel, political party, movement to protect wildlife);
informal reference groups do not have a clear, hierarchical structure. The relationship is determined by common interests (a local football team, a club for fans of Korean popular music).

According to the degree of self-acceptance in the group

According to the degree of importance and acceptance of oneself in the group, referent associations are divided into:

primary, where all members are closely connected with each other, everyone is given attention, connections between people are determined by feelings, affection (family, company of close friends, brothers);
secondary, where the members of the association do not have special feelings for each other, interact infrequently, usually only out of necessity (neighbors, residents of the same area, team at work).

Range of reference values in different laboratories

Each laboratory conducting diagnostics is guided by its own results obtained during research, and only where generally accepted medical standards exist does it refer to them. This is where the difference appears, which frightens patients who have undergone tests at different diagnostic institutions.

A doctor studying test results is not always guided by the reference data of a particular laboratory. Practical knowledge may prompt him that the upper or lower limit in the resulting analysis may differ in a particular area (due to unfavorable ecology or climatic conditions). He has the right to rely on data in the medical literature, or prescribe diagnostics in another laboratory. It is likely that an indicator that poses some threat to the patient's condition will be included in the reference interval in an institution using other numbers or calculation systems.

Differences

The concept of reference should not be confused with other values (keys or identifiers) that uniquely identify a data element but provide access to it only through a non-trivial lookup operation in some table data structure.

References are widely used in programming, especially for efficiently passing large or volatile data as arguments to procedures or for exchanging such data among different applications. In particular, a reference can point to a variable or record that contains references to other data. This idea is the basis of indirect addressing and many related data structures such as linked lists. Links can cause significant complexity in a program, partly due to the possibility of dangling and wild links, and partly because the topology of the linked data is a directed graph, the analysis of which can be quite complex.

References increase flexibility in where objects can be stored, how they are distributed, and how they are passed between regions of code.

Important point. As long as the data link can be accessed, the data can be accessed through it, the data itself does not need to be moved. They also make it easier to share data between different areas of code. Everyone keeps a link to it.

What does a result outside the reference values mean?

Unlike the norm indicators established by international standards, an indicator that goes beyond the boundaries in one direction or another is not a sentence or even a diagnosis. It's just a certain result. Reference values are obtained on the basis of statistical data, but are not a biological law or a mandatory limit for a healthy person. To correctly navigate inflated or underestimated figures, it is recommended:

carry out repeated diagnostics in another laboratory;
exclude possible factors that distort the clinical picture;
do the analysis again in the same laboratory, after some time, and consider the average of all analyzes as the result obtained.

If diagnostics showed an increased content of a particular element, this may be explained by objective reasons, or errors in the equipment and methods used. A reference value of 0 simply means that the laboratory does not have relevant statistics.

Linguistic sign

The very concept of a linguistic sign is a combination of content and expression, the former of which may refer to entities in the world or refer to more abstract concepts such as "thought". Certain parts of speech exist only to express reference, namely anaphors such as pronouns. A subset of reflexives expresses the joint reference of two participants in a sentence. These could be agent (actor) and patient (acted), as in “the man washed himself,” topic and recipient, as in “I showed Mary to myself,” or various other possible combinations. But it is not only the humanities that have absorbed this term. The exact sciences also boast their own versions of this term, such as the dispersion and referentiality of light in physics. But a much more extensive definition of reference is given to us by computer science, which is discussed below.

Factors influencing the reference value

The reference value is influenced by endogenous and exogenous factors of negative significance (diseases, inflammations, infections, colds, etc.). But it is no less susceptible to the simple conditions of everyday existence. In women, these are hormonal disorders (menstruation, pregnancy, ovulation, menopause). Common to all may be:

psycho-emotional disorders and stress;
overwork and physical exertion;
improper or untimely nutrition;
physiotherapy;
taking alcohol or medications;
time of day at which the analysis was carried out.

We should not forget about the individual characteristics of each organism. They may involve going beyond the statistical indicator, but indicate the healthy state of a certain person.

Features of the definition

A synonym for reference is reference. References can take many forms: thought, auditory perception (onomatopoeia), visual (text), olfactory or tactile, emotional state, relationship with others, space-time coordinate, symbolic or alphanumeric, physical object or energy projection. In some cases, techniques are used that deliberately hide the link from some observers. Like in cryptography.

References are mentioned in many areas of human activity and knowledge, the term taking on shades of meaning specific to the context in which it is used. Some of them are described in the sections below.

Reference range norms in children

The reference range in childhood is established based on the age indicator. The characteristics of the child’s body and the intensity of its development imply certain numbers for each age indicator. Not only are they different from adults, but they are also different at each stage of growth. For example, the hemoglobin indicator on the first day is 179-241, in the first month of life it should be 114-176, and from one year to 6 the reference value is 110-139. Children also have distorting factors and individual characteristics in which the result may be out of bounds.

Reference interval in tests in adults

In tests issued to adults, the age category and gender of the patient being studied must be taken into account. You should not immediately look for standards that should be present in indicators of relative health. Only the attending physician who is familiar with all the components can decipher the analysis. He may advise changing the laboratory or eliminating possible objective distorting factors, monitoring compliance with the necessary conditions, and taking into account the individual characteristics of his patient.

Normal for pregnant women

The norm for pregnant women is established depending on the period and is determined according to a special table (if we are talking about human chorionic gonadotropin. But the discrepancy between the norm numbers is quite significant, so the doctor is responsible for deciphering the analysis indicators. There is no need to draw any hasty conclusions until repeated studies are carried out.

Reference values in blood tests

A blood test is not only biochemical indicators. It is often prescribed to determine other data about the presence or absence of certain components. Each type of blood test has its own established data, combined into special tables. We should not forget about the difference in distortion due to objective reasons, the difference determined by age and gender.

Tumor markers: reference values

Decoding the analysis for tumor markers is the exclusive prerogative of the oncologist. The final diagnosis may depend on each specific species, its quantity and the fact of its presence. But only the fact of their existence. if they are in smaller quantities than the reference value dictates, it means nothing. Tumor markers can normally be present in a healthy person. It's not about the fact of presence, but about its combination with other indicators.

Reference glucose values for diabetes mellitus

If all the necessary conditions for taking the test are met (blood from a vein and strictly on an empty stomach), there are certain standards that should be reflected in the analysis:

in adults - 4.1–5.9 mmol/l;
in infants up to 1 month. - 2.8–4.4 mmol/l.
in children from one month to 14 years - 3.3–5.6 mmol/l;
in older people (from 60 years of age) and pregnant women, levels can reach 4.6–6.7 mmol/l.

Discrepancies by insignificant numbers do not mean the presence of diabetes mellitus. Its presence is established after several laboratory tests carried out repeatedly. Insulin also plays an important role in this process, the reference values of which are also important when making a diagnosis.

Hormone reference values

The human body produces a significant amount of hormones produced by the organs of the endocrine system. Each of them has its own approximate reference values, determined by the corresponding hormone tests. The concept of relative normal may vary depending on gender, age and physiological state being studied.

Reference TSH values

Analysis for thyroid-stimulating hormone plays an important role in the diagnosis of negative conditions caused by TSH deficiency in the body. The peculiarity of determining the reference values of thyrotropin consists in age, gender and the available indications for its measurement (external and internal signs indicating its deficiency or excess). Only an endocrinologist should decide on the need for therapy and establish a specific diagnosis, based on all the necessary diagnostic indicators.

Introduction

In accordance with WHO recommendations, national regulatory authorities in the field of medicines circulation in the Russian Federation have in recent years paid special attention to the creation of a system for the rational use of medicines.
The regulatory document of the Ministry of Health of the Russian Federation defines the Strategy for drug provision to the population until 2025, which was approved by Order of the Ministry of Health dated February 13, 2013 No. 66 (as amended on April 7, 2016) “On approval of the Strategy for drug provision to the population of the Russian Federation for the period until 2025 year and the plan for its implementation." One of the key provisions of the rational use system is independent objective professional information about drugs, which is an important factor influencing the competence and awareness of medical personnel. The problem of rational use of drugs includes several areas, including the use of drugs with proven effectiveness and safety and the possibility of preventing unwanted side reactions of drugs [2].

For a number of reasons, specialists in the healthcare system in the Russian Federation often do not have objective and timely professional information about drugs due to the increase in the number of circulating drugs on the pharmaceutical market, the predominance of generic drugs of domestic and imported production and the lack of accessible information databases on their interchangeability with reference drugs [3].

In accordance with federal laws dated April 12, 2010 No. 61-FZ “On the circulation of medicines” and dated December 22, 2014 No. 429-FZ “On amendments to the Federal Law “On the circulation of medicines” in the Russian Federation and introduced new concepts: “reference medicinal product”, “interchangeable medicinal products”. The wording of the concept of “generic medicinal product” was changed and Article 27.1 “Procedure for determining the interchangeability of medicinal products for medical use” was introduced for the first time.

According to a number of studies, the most effective and safe drug among all trade names corresponding to one international nonproprietary name (INN) is the reference drug. However, the use of a reproduced drug instead of a reference drug, even for economic reasons, can be justified only if the specialist is convinced that this will not reduce the effectiveness and safety of pharmacotherapy.

In accordance with the current order of the Ministry of Health of the Russian Federation dated January 14, 2019 No. 4n “On approval of the procedure for prescribing medicines, forms of prescription forms for medicines, the procedure for completing these forms, their recording and storage”, “the prescription of medicines is carried out by a medical worker according to international nonproprietary name (INN), and in its absence - by group or chemical name. In the absence of an INN and a group or chemical name of a medicinal product, the medicinal product is prescribed by a medical professional according to its trade name” [4]. If earlier in the choice of a particular drug the determining role could be played by the loyalty of the attending physician to a particular drug, today this factor is the personal preferences of the buyer, coupled with the recommendations of the pharmacy specialist dispensing the drug.

Prospects for resolving these issues in order to improve the quality of pharmaceutical care are outlined in the order of the Government of the Russian Federation dated January 12, 2018 No. 9-r “Development of competition in healthcare,” which approved an action plan (“road map”). This plan provides for the introduction of a number of changes to the legal regulation relating to the interchangeability of medicines in particular. Among other things, the “road map” provides for ensuring the functioning of the institution of drug interchangeability, including the formation of a list of reference drugs, the formation of a register of standard instructions for the use of interchangeable drugs.

In the Russian Federation, among the official information sources about drugs, the first position is occupied by the online resource “State Register of Medicines” (GRLS) as an independent, accurate, structured, objective and verified source of information. GRLS is a publication of the Russian Ministry of Health, which includes a list of domestic and foreign drugs (medicinal products and pharmaceutical substances) approved for medical use in our country. Each drug registered in the Russian Federation corresponds to a page in the GRLS system.

GRLS contains a list of medicines that have passed state registration, while all medicines are presented with registration certificates consisting of 12 sections, allowing you to obtain the following information:

Registration certificate number, registration date, re-registration date, date of introduction into civil circulation.

Name of the holder or holder of the marketing authorization, indicating the country.

Trade name of the drug.

International nonproprietary, or group, or chemical name.

Release form indicating the dosage form, dosage, expiration date, storage conditions.

Information about the stages of production, including stages of production, address of the manufacturer, manufacturer, country.

Instructions for using the drug via the active “Show instructions” button.

Regulatory documents indicating the number of the regulatory document, year, change number.

Pharmacotherapeutic group.

Anatomical and therapeutic chemical classification indicating the drug code.

Pharmaceutical substance indicating the international nonproprietary, or group, or chemical name, manufacturer, address of the manufacturer.

Special marks include: the presence of drugs in the list of vital and essential drugs; the presence in the medicine of narcotic drugs, psychotropic substances and their precursors, subject to control in the Russian Federation in accordance with the legislation of the Russian Federation, international treaties of the Russian Federation, including the Single Convention on Narcotic Drugs of 1961 and the Convention on Psychotropic Substances of 1971; referentiality and interchangeability of drugs.

The great advantage of using the GRLS resource to obtain information about drugs is that it provides information about registration and re-registration, about manufacturers at all stages of production, information about the pharmaceutical substance and a scanned version of the instructions for use of the drug from the developer. In addition, the resource contains valuable information about the presence of this drug in the list of vital and essential drugs, about the reference drug, the interchangeability of the drug, and the date of re-registration of the drug, which today is not presented in a systematic form anywhere else.

Due to the great significance of the issues identified, the authors conducted a study of the awareness of medical workers in the Irkutsk region on the issues of referenceability and interchangeability of drugs, and also analyzed options for search work in the GRLS system.

Reference values in stool

Stool tests are prescribed for many pathologies of the digestive system or suspicions of parasitic infestations, so the reference value may concern consistency, color, content of parasites, larvae or eggs, the presence of mucus or blood, and other reactions - all this is information that the doctor will decipher.

By the way, read more on this topic: Stool analysis for scatology

Obtaining data from laboratory tests is a way to get an idea of the nature of the pathology or to ensure its absence. A person’s concern about his own health is quite understandable, and when he asks: reference values in analyzes - what are they - is quite understandable. But reference values are not a dogma or a biological law, but just statistical data obtained by a certain laboratory when examining healthy people.

Reference group influence

Reference groups are a tool for influencing different groups of people. A reference group can influence a person:

Help with the socialization process. The work team welcomes the newcomer, tells them what rules and requirements apply in the company, and helps them comply with them.
The process of self-education. When interacting with a reference group, a person adjusts his own self-esteem, breadth of outlook, and ideas about the world. A person acquires many social roles and learns to behave correctly in different situations.
Social comparison. Many people have a need to compare themselves with others. With the help of a reference group, a person evaluates his behavior, success, and status in society.
Comfort (ability to adapt). Sometimes people strive to consciously imitate the behavior of groups that are significant to them. For example, a younger brother admires his older brother, copies his manner of speaking, dressing, and adopts some of his hobbies.