Community Health seminars 3 &4 Flashcards
why is the planning cycle relevant to doctors
doctors need to influence services available to patients
define (impact) evaluation
assessment of whether a service achieves its objectives - oxford handbook
define (process) evaluation
process that attempts to determine as systematically and objectively as possible the relevance, effectiveness and impact of activities in the light of their objectives - epidemiology definition
give 2 e.g.’s of health care evaluation
single intervention - RCT new drug
health technology assessment
health economic evaluation
evaluation of public health interventions
what framework is used for health service evaluation
donabedian
what are the 3 aspects of donebedian evaluation
structure
process
outcome
define structure (donebedian)
what there is (buildings, staff, equipment)
e.g. number of beds in ITU per 100 patients
define process (donebedian)
what is done
e.g. the process through which patients go through A&E
define outcome (donebedian)
classification of health outcomes
give 4 outcome measures (donebedian)
mortality
morbidity
quality of life/ PROM (patient reported outcome measures)
patient satisfaction
five D’s for classifying outcome (donebedian)
death disease disability discomfort dissatisfaction
what is output (donebedian)
what you hope the patient will do when they are given info
e.g. change diet, regular glucose monitoring, exercise, medication use
if output happens you should be able to achieve outcomes
explain he cause and effect chain for output and outcomes (donebedian)
short term outputs need to be linked to long term outcomes so you can show the process worked
define PROM
measure health gain in patients undergoing
- hip replacement
- knee replacement
- varicose vein
- groin hernia surgery
based on questionnaires before and after the surgery
e.g. of PROM
oxford hip score
give 5 issues with health outcomes
- link between health services and health outcomes difficult to establish due to multiple factors
- time lag between service and outcome long
- large sample sizes needed to detect statistically significant effects
- data availability
- data quality
what are the structure, process and outcome for hip replacement and how you measure them
- structure - surgeons/ theatre/ materials - measure = waiting times
- process - gp visit, referal, hsopital, pre-op etc. - measure = time from gp-apt, correct identification of risk
- outcome - QoL - measure - no wks physio required?
what are the structure, process and outcome for diabetes MX and how you measure them
- structure - DAFNE (1), DESMOND (2), diabetic specialist nurse, medication - measure = knowledge questionnaire
- process - annual diabetic review, annual opthamology, podiatry - measure = no. referals vs no. attending
- outcome - HBA1C every 3m - measure HBA1C?
what are the structure, process and outcome for breast Ca screening and how you measure them
- structure - radiologist/1000, no. working USS machines, no. specialist nurses - measure = staff survey, national guidance
- process - invite letter, attend screening - measure = no. letters sent/received vs no. attending clinic, no. screenings
- outcome - mortality, no. early stage/symptomatic identified - measure mortality/ morbidity
what are Maxwells dimensions of quality (x6)
3A’s and 3E’s
- effectiveness - does intervention/service produce desired effect
- efficiency - is output maximised for a given input
- equity - are patients being treated fairly
- acceptability - how acceptable is the service offered to the people needing it
- accessibility - is the service provided (geography, cost, information)
- appropriateness - is the right treatment being given to the right people at the right time
example of qualitative evaluation (x4)
- observation (participant and non-participant observation)
- focus group
- interview
- review documents
consult relative stakeholders as appropriate
example of quantitative evaluation (x4)
- routinely collected data e.g. mortality, hosp admission
- review records
- surveys
- epidemiological studies
basic approach for evaluation appropriate to the health service being evaluated
- define what the service is
- what are the aims and objectives of the service (stated and appropriate)
- framework - structure, process, outcome
- methodology to be used - qualitative, quantitative, mixed methods
- results, conclusion, recommendations
epidemiology
the frequency, distribution and determinants of diseases and health-related states in populations in order to prevent and control disease
incidence
number of new cases within a specified period of time
prevalence
number of existing cases at a point in time
what is person-time
a measure of time at risk (used to calculate incidence rate)
incidence rate equation
Number of persons who have become cases in a given time period /
Total person-time at risk during that period
absolute risk
gives a feel for the actual numbers involved e.g. 50 deaths/1000 population
(your risk of developing the disease over a time period)
e.g. risk of developing lung cancer
attributable risk
rate of disease in the exposed that may be attributed to the exposure
Its about the size of effect in absolute terms i.e. gives a feel for the public health impact (if causality is assumed)
a type of absolute risk
rate of lung cancer in smokers that is due to smoking
how to you work out attributable risk
incidence in exposed MINUS incidence in unexposed
relative risk
rate of disease in exposed compared to unexposed
If no risk = 1
Relative risk <1 = reduced the risk
>1 = increased risk
e.g. ratio of lung cancer in smokers vs non-smokers
bias
a systematic deviation from the untrue estimation of the association between exposure and outcome
i.e. a systematic error which leads to distortion of the true underlying association
types of bias (x2)
selection bias
information bias
what is selection bias
a systematic error in the selection of study participants or the allocation of participants to different study groups
what is information bias
a systematic error in the measurement or classification of exposure or outcome
sources of information bias (x3)
observer (observer bias)
participant (recall bias)
instrument (wrongly calibrated instrument)
confounding
the situation where a factor is associated with the exposure of interest and independently influences the outcome (but does not lie on the causal pathway)
reverse causality
e.g. case-control study examining the hypothesis that stress causes HTN. the results are consistent with stress causing HTN - BUT could HTN have caused stress
odds ratio
a measure of association between as exposure and an outcome
(The odds ratio represents the odds that an outcome will occur given a particular exposure, compared to the odds of the outcome occurring in the absence of that exposure.)
odd of lung ca if you smoke vs odds of lung ca if you don’t smoke
when would you use relative risk
used when the study involves comparing the likelihood, or chance, of an event occurring between two groups.
It is the risk in one category, relative to another, i.e. has no units
It tells us about the strength of association between a risk factor and a disease
when do you you use odds ratio
control studies
confidence interval
a range of values that you can be 95% certain contains the true mean of the population
If associations are not causal, what are the possible explanations?
Bias
Confounding
Reverse causation
Chance
prevention paradox
= a preventative measure which brings much benefit to the population, but offer little to each participating individual
e.g. statins for the primary prevention of CVD
how do you work out percentage changes in relative risk associated with 1 cigarette a day vs 20 cigarettes a day
RR of 20 cigarettes a day MINUS RR of 1 cig per day
see example in notes
what factors influence what and how much we eat (name 5)
- education (cooking skills, what to eat)
- money
- advertising, promotions (TV, shops)
- emotional eating
mental health (depression) - employment (shift work)
- social influence (eating out with friends, takeaways)
- reduced physical activity
- early developmental factors
- characteristics of food (energy density, macronutrients composition, satiety + satiation, portion size)
define malnutrition
refers to deficiencies, excess or imbalances in a person’s intake of energy and or nutrients.
what does malnutrition include
It covers ‘undernutrition’ which includes stunting (low height for age), wasting (low weight for height), underweight (low weight for age) + micronutrient deficiencies of insufficiencies.
it also covers overweight, obestity and diest related non-communicable diseases e.g. diabetes
chronic conditions requiring nutritional support (x5)
cancer CF coeliac IBD type 2 DM failure to thrive
early influences on feeding behaviour
- maternal diet + taste preference development
- role of breast feeding for taste preference and bodyweight regulation
- parenting practices
how does maternal diet effect feeding behaviour
- taste and olfactory systems are capable of detecting flavour info prior to birth
- amniotic fluid is influenced by maternal diet
- inutero environment influences taste exposure
how does breastfeeding effect feeding behaviour
- children have greater preference for flavours exposed to them in amniotic fluid/ breast milk/ formula
- protects against obesity
- encourages better appetite regulation
impact of socioeconomic on breastfeeding
- prev low among very young mothers + disadvantaged socioeconomic groups –> widening health inequalities
- 46% breastfeed in deprived areas compared to 65% in least deprived
advantages of breastfeeding (x3)
- acceptance of novel foods during weaning
- children who are breastfed are less picky eaters in childhood
- have diet richer in fruit and veg in breastfed >3m
how does parenting practices effect feeding behaviour
- male child aged 4
- food refusal based on texture and taste
- selective picky eating
- long meals times >40mins
- meal times ‘very distressing’
caregivers use tactics such as coercion, persuasion, contingencies to get children to consume new foods –> using food as an incentive to eat novel foods increases the liking for reward and decrease liking for novel food
good parenting practices for feeding behaviour
- modelling ‘healthful’ eating behaviours
- providing a variety of foods
- avoiding pressure to eat
- responsible feeding (recognise hunger and fullness cues)
- not using food as a reward
- authoritative parenting
- avoid indulgent/ neglectful feeding practices
what characterises non-organic feeding disorders
feeding aversion, food refusal, food selectivity, fussy eaters
high prev in children <6yrs
parents often use maladaptive parental feeding practices
what are 3 eating disorders
anorexia nervosa (0.5-1%) bulimia nervosa (0.8%) binge-eating disorder (2.2%)
define eating disorder
clinically meaningful behavioural or psychological pattern having to do with eating or weight that is associated with distress, disability or with substantially increased morbidity or mortality
give examples of disordered eating
restraint, strict dieting, dis-inhibition, emotional eating, binge-eating, night eating, weight and shape concern
3 basic forms of dieting
- restrict the total amount of food eaten e.g. 5:2
- do not eat certain food types e.g. atkins
- avoid eating for long periods of time
how much of UK population diet
2/3 population restrict intake or diet to loose weight
problems with dieting (x3)
- RF for developing eating disorder in SOME individuals
- dieting –> loss of lean body mass, not just fat
- dieting slows metabolic rate and energy expenditure
- chronic dieting may disrupt ‘normal’ appetite responses and increase subjective sensations of hunger
- long term weight loss is challenging (most people plateau then regain)
- weight cycling (from repeated diet relapse) often leads to ‘overshoot’ and may accelerate weight gain
- non-obese dieters are at increased risk of overshoot compared to obese
why is dieting difficult for some patients
those susceptible to obesity (and who try to diet) appear particularly:
- unresponsive to internal cues that signal satiety (when overeating) and hunger (when dieting)
- vulnerable to external cues that signal availability of palatable food
what environmental cue may cause obesity
portion sizes (most people don't really know what constitutes an appropriate portion size for many food and beverages)
what is the population approach to prevention
a preventative measure delivered on a population wide basis which seeks to shift the risk factor distribution curve (e.g. reduce dietary salt through legislation)
what is high risk approach to prevention
seeks to identify individuals above a chosen cut off and treat them (e.g. tx people w/ HTN >140/90)
