WONCA International Classification Committee

DALY

An acronym for disability adjusted life years.

DATA PROCESSING

Conversion of data collected about patients or people into a form where it is easily stored and easily accessed for analysis. The term is sometimes used for statistical analysis of data by a computer.

DATA-SET

Raw data gathered by investigators.

DEATH RATE

The estimated proportion of a population that dies during a year (the period most often used). The numerator is the number of persons who have died during the year, and the denominator is mid-year population.

DECISION TREE

A graphic illustration of possible ways of solving a problem, showing the various outcomes at each stage in the problem solving process.

DEDUCTION

A method of problem solving which uses general knowledge to reach specific conclusions.

DEMAND FOR HEALTH SERVICES

Willingness and/or ability to seek, use, and, in some settings, pay for health services. Sometimes further subdivided :
1. Expressed demand - which equates with use.
2. Potential demand - which equates with need.

DELPHI TECHNIQUE

A method of gaining information about a problem from a panel of experts without bringing them together. It employs a questionnaire with cycles of feedback rather than face-to-face discussion.

DEMOGRAPHY

The description of populations' size, density, sex and age distribution, fertility, growth and mortality and other vital statistics and their interaction with social and economic conditions.

DENOMINATOR

The lower portion of a fraction used to calculate a population based rate or ratio.

DENOMINATOR PROBLEM

refers to the difficulty sometimes encountered in defining precisely the practice population or the population at risk. This causes problems in the calculation of comparative rates and ratios.

DENSITY

The number of items (practices, patients, people) in relation to the space available.

DEPENDENCY RATIO

Proportion of dependent persons, often meaning children under the age of 15 and elderly over the age of 65, in a population. Number of dependent persons divided by the number of the rest of the population.

DEPENDENT VARIABLE

A variable which depends on another variable in a study. The dependent variable is analyzed in relation to independent variables. The dependent variable can be considered as the outcome variable, and the independent variable, as predictor variables.

DEPUTIZING SERVICE

See EMERGENCY CALL SERVICE.

DESCRIPTIVE STATISTICS

Statistics where indicators characterize the score distribution for a particular sample. This can be the mean, standard deviation, range and missing data.

DESCRIPTIVE STUDY

An observational study which does not test a specific hypothesis by performing an experiment.

DETERMINANT

Any thing that brings about changes in health status.

DIAGNOSIS

A formal statement of the provider's understanding of a health problem presented by a patient, family or community. This may be limited to level of symptoms. The term covers both the process and its outcome and in the case of a patient, represents the formal medical establishment of an episode.
1. Principal diagnosis : (main diagnosis) - the most important problem, as determined by the health care provider.
2. Associated diagnosis : another diagnosis made at the same time as the principal diagnosis.
3. Concurrent diagnosis : one which exists at the time of the encounter, but which is not dealt with at the en-counter.

DIAGNOSIS RELATED GROUPS

Method to define case-mix taking into account diagnostic categories and procedures. Originally the approach involved coding with ICD-9-CM and grouping by homogeneous costs and used major diagnosis, length of stay, secondary diagnosis, surgical procedure, age and type of service required.

DIAGNOSTIC CATEGORIES

In general practice three diagnostic categories are used :
1. Pathological/pathophysiological diagnosis having a proven pathological/pathophysiological substrate and/or proven etiology.
2. Symptom diagnosis using a symptom or complaint of the patient as the best medical label for the episode.
3. Nosological diagnosisusing a symptom complex based on consensus between physicians, but which lacks a proven pathological or pathophysiological basis or etiology.

DIAGNOSTIC CRITERIA

The symptoms and complaints together with the objective signs and test results which are essential for labelling a health problem, making a diagnosis.

DIAGNOSTIC INDEX

A system by a practice, in which the episodes are recorded by diagnosis, date of presentation, patient name (or number), age and gender. The index helps in the retrieval of medical records for cohorts of patients with similar health problems, and may be used to facilitate follow-up.

DIAGNOSTIC PROCEDURE

Procedure used to arrive at a diagnosis. Can include the taking of the history and the performance of a physical examination, but usually refers to additional diagnostic procedures, such as laboratory or radiologic procedures.

DIAGNOSTIC SERVICE

The assessment of any problem by history, physical examination, laboratory, imaging, or other examinations performed either inside or outside the office setting.

DIMENSION

A distinct component of a multidimensional construct that can be specified. Physical and mental health are dimensions of overall health.

DISABILITY

Any restriction or lack (resulting from an impairment) of ability to perform an activity in the manner or within the range considered normal for a human being.

DISEASE

A physiological or psychological dysfunction. It should be distinguished from illness, which is the subjective state of the person who feels aware of not being well; and from sickness which is a state of social dysfunction, ie a role that the individual assumes when ill.
Disease can also be construed as a more narrow concept discernable from syndrome and complaint : a biological dysfunction on basis of well-known pathological or pathophysiological processes or with a well-known aetiology.
Disease can be discerned from :
1. Syndrome which is a presumed biological dysfunction of which the knowledge of causative pathological or pathophysiological processes is not accepted as conclusive for seeing it as a DISEASE, according to the literature. A dysfunction or health problem is considered a DISEASE by professional consensus. If this does not exist it is a syndrome.
2. Complaint is not part of a DISEASE or syndrome.
Disease is a concept of reality and can therefore exist without a physician's judgement. DISEASE, syndrome and complaint are congruent with diagnostic categories.

DISEASE LABEL

A diagnosis which describes the health state of a person. Often stigmatising diagnoses are covered by this term.

DISEASE, PRECLINICAL

A health problem before it is experienced by the individual and before it can be detected by any diagnostic means.

DISEASE, SUBCLINICAL

A health problem which can be detected by special diagnostic test, but which gives rise to no signs or symptoms.

DISORDER

Disturbance of the normal health status. It is used in an attempt to generalize rather than use the more specific term disease.

DISTRIBUTION

The manner in which a characteristic is dispersed amongst the members of a class.

DISTRICT PHYSICIAN

A primary physician who accepts continuing responsibility for the general health care of all persons living in a defined geographical area. In addition to his/her function as a general practitioner/family physician, he/she often functions as a community physician with certain administrative duties for the organization of primary medical services in the district. He/she is usually employed by a government agency (local or central) either on a full-time or part-time basis.

DOCTOR-PATIENT RELATIONSHIP

Communication and rapport between the doctor and the patient.

DOMICILIARY CONSULTATION

This describes the consultation, where the doctor in the patient's home, assesses his or her health and provides advice/treatment.

DOUBLE-BLIND TRIAL

A trial involving two study groups, one receiving active drug and the other receiving placebo, and where neither the patients nor the clinicians know which is which. This eliminates bias from the assessment of the results of the trial.

DROPOUT

A person who has been enrolled in a study, but has left it for any reason.

DURATION OF AN ENCOUNTER

The time spent in face to face contact with the doctor during a patient encounter.