Pre-Module Learning – Concepts surrounding Health and Disease 2024/2025 PDF

Stage 4 Pathology 2024/2025 Pre-Module Learning – Concepts surrounding Health and Disease What is your definition of health?..................................................................................

Stage 4 Pathology 2024/2025 Pre-Module Learning – Concepts surrounding Health and Disease What is your definition of health?................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ Definition of Health  According to The World Health Organisation (WHO) the term “health” is defined as: “Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.”  According to The National Cancer Institute the term “disease” is defined as: An abnormal condition that affects the structure or function of part or all of the body and is usually associated with specific signs and symptoms. What is it meant by “signs and symptoms?” Define these terms below: SIGNS: SYMPTOMS: Critical consideration into “normality within medicine”  It is important to consider what is categorised as “normal” within clinical practice and medical pursuits as this typically correlates to our understood meaning of health status and what is “healthy”.  Definitions for terms such as this can have clear implications for patients, medical professionals and regulations within clinical practice (Catita et al., 2020)  Normality has no singular meaning given to it, and thus, the fluctuation of this meaning complicates our understanding of health within medicine.  According to Biostatistical Theory and from a naturistic approach “the absence of pathological conditions” is enough to imply “normality”. 1 Stage 4 Pathology 2024/2025  BUT… the question is then; “Does absence of disease or conditions indicate that the individual is healthy?”  From a statistical viewpoint “normality” indicates the frequency of a given condition in a defined population.  Yet, some diseases occur with high frequency within population groups, and they may still be considered normal.  So, what does “normal” look like?...  The typical distribution of health indicators follows a normal distribution in the population. This can be noted as bell-shaped or a ‘Gaussian’ curve.  Properties of the Curve:  The Gaussian or bell-shaped curve illustrates the distribution of a random population.  All Gaussian curves have certain properties: 1) the total area under the curve and above the x-axis is one 2) the curve is bell shaped 3) the curve is symmetrical about the mean of the distribution. Every Gaussian curve encompasses 68% of the area of the curve in +1 and –1 Standard Deviation along the x-axis.  If an experiment is repeated many times, and if the errors are purely random, then the results will cluster symmetrically around the mean value  The more times the experiment is repeated, the more closely the result approaches an ideal smooth curve  Even from a small set of results the statistical parameters that describe the large set can make estimates of statistical behaviour from the small number of measurements  The central point is the mean or average value and 68% of such a population will fall between +/- 1 standard deviation of the mean.  Applying limits to the curve produces 2 cut-off points, below and above which a value might be considered abnormal 2 Stage 4 Pathology 2024/2025  However, a grey area exists, where a small percentage of people falling in abnormal zones will remain healthy.  It is also important to note that a normal distribution does not always mean healthy e.g. blood cholesterol concentration in UK higher than ideal levels  Therefore, the term REFERENCE RANGE is often more appropriate than NORMAL range e.g. haemoglobin range (female)-11.5-16 g/dl Health Data and Concepts of Measuring Disease  There is a need to plan health services and review the effects of existing healthcare.  We must have an accurate and contemporary picture of the range and extent of health problems in the relevant population to implement any future changes.  Any population will have significant variations within it and therefore, health is often examined within various groups so a larger picture can be determined. e.g. different socio-economic groups, different regions with different environments. Routine Information Collection: How do we generate this information? 1. Population data = census information  A census is a count of all people and households are in the country  It provides population statistics from a national to neighbourhood level for government, local authorities, business and communities.  Details are collected from the head of the household who is required by law to list names, sex, country of birth, employment, education, means of transport to work etc.  Subject to inaccuracies e.g. the homeless excluded and occupational details can be exaggerated! 2. Mortality Data  Refers to how many people have died, their age upon passing, during which period and from which diseases = registrar information.  Registration of all deaths has been compulsory since 1874.  Requires a qualified informant (close relative of the deceased) to attend the local registrar’s office within 5 days of the death to present the medical certificate of 3 Stage 4 Pathology 2024/2025 cause of death as well as the date and place of death and details of the deceased  A registered medical practitioner who issues the certificate of death as the immediate cause of death as well as underlying causes.  The registrar on receipt of these details will issue the death certificate and returns a copy to the OPCS 3. Morbidity Data Morbidity = the impact of disease on an individual or population group i.e. detrimental effects such as pain or disability  Morbidity data – how many cases of which diseases have occurred, in what time span, whether or not numbers have increased and how they have spread = medical information from hospitals and GPs 4. Hospital data  Hospital Activity Analysis (HAA) - Records of all hospital admissions (excluding maternity or mental illness) e.g. clinical reason for admission, personal details (excluding name) are kept by the Regional Health authority  Hospital Inpatient Enquiry (HIPE) - HIPE is a computer-based system designed to collect demographic, clinical and administrative data on discharges and deaths from acute hospitals nationally.  Annual Hospital returns (SH3) - Individual wards provide specialised information on daily activity collected locally but collated centrally - Provides specific information e.g number of diabetic renal patients receiving dialysis as in-patients and as out-patients  Mental Health Enquiry - Records data on psychiatric inpatients  Systems all rely on medical staff to provide regular and accurate information.  The system counts events and NOT people.  All these systems disregard the burden and impact of disease on the people involved e.g. the person’s perception of their state of health 5. Community Data 4 Stage 4 Pathology 2024/2025  GP list – average list 2275 patients per GP and 60% consult GP in any one year with average number of consultations ~ 4.5 p.a - Age-sex register = file of all patients on GP list with details of repeat prescriptions, infectious illness etc. Also info to implement special measures and programmes e.g. home visits, vaccinations, cervical screening etc. - Problems with maintaining current and accurate information  General Household survey - Began 1971 collecting annual data from a rotating sample of 15, 000 private households (31,000 people) on health, employment, leisure activities as well as health data on medication, smoking, episodes of illness and disability etc.  Cancer register - Organised regionally where all new cases of neoplasms and pre-malignant states are recorded according to area, sex, date, age, occupation, site and type of tumour  Other registers include psychiatric illness, ischaemic heart disease, child abuse, stroke and trauma Measuring Disease  The Rate: includes 3 components - The Numerator = number of people in the population who are experiencing the event of interest e.g deaths, births - The Denominator = number in the specific population considered e.g. males over 80 - The Time – refers to the specified period (time) during which the event took place e.g. the first 6 months between 1990-2000  Crude rate - Rate in terms of the entire population e.g the death rate is expressed as the numbers who have died compared to the general population in one year (x1000 = rate per thousand)  Specific rates - The number of events occurring in a sub-group of the population. Common sub-groupings are age, sex, occupation, race, social class - E.g. the annual age-specific death of females in age group 18-35 compared to the number of females in this population ( x 1000=specific rate per thousand).  Mortality rates 5 Stage 4 Pathology 2024/2025 - Total number of deaths in the population in defined period/number in the population at mid-period  Morbidity rates - Incidence and Prevalence - Not all diseases are uniformly fatal or show equal morbidity. Morbidity is measured as: Incidence: number of new cases of disease occurring per unit of population per unit of time  e.g. 5 cases of CJD in 18–40-year-old men, per year - Incidence rate per 10,000: - Number of new cases of a disease in each period/total population at risk over the same period x 10,000 Prevalence: number of all existing cases of the disease at a point in time  e.g. 20,000 current cases of HIV in UK - Prevalence rate per 10 000: - Number of cases existing during given period/total population at risk during that time x 10,000 Global Data The World Health Organisation (WHO) 2002 REPORT re current largest risks to health - “The report identifies the top ten risks, globally and regionally, in terms of the burden of disease they cause. 10 leading risk factors globally are: underweight; unsafe sex; high blood pressure; tobacco consumption; alcohol consumption; unsafe water, sanitation and hygiene; iron deficiency; indoor smoke from solid fuels; high cholesterol; and obesity. - “Together, these account for more than one-third of all deaths worldwide” o “At least 30% of all disease burden occurring in many developing countries, such as those in sub-Saharan Africa and South-East Asia, results from fewer than five of the ten risks listed above. Underweight alone accounts for over three million childhood deaths a year in developing countries. o NB. WHO does not include all countries - 194 member states (WHO, 2015). 6 Stage 4 Pathology 2024/2025 Catita, M., Águas, A. and Morgado, P. (2020) Normality in medicine: a critical review. Philosophy, Ethics, and Humanities in Medicine. 15, 3 (2020). https://doi.org/10.1186/s13010-020-00087-2 7