Logros de aprendizaje que involucra activamente a los estudiantes Hipótesis especifica 1

Evidence-based practice

Evidence based practice is the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients

Sackett et al., 1996

Evidence-based practice is graded according to a system which attributes high evidence to the ‘gold standard’ research method of the randomized controlled trial (RCT) and lower evidence to studies of a more descriptive nature (Table 3a.1).

Table 3a.1 The fi ve strengths of research evidence Type Strength of evidence

I Strong evidence from at least one systematic review of multiple well-designed RCTs

II Strong evidence from at least one properly designed RCT of appropriate size

III Evidence for well-designed trials without randomization, single group pre-post, cohort, time series or matched case-control studies IV Evidence from well-designed non-experimental studies from more

than one centre or research group

V Opinions of respected authorities, based on clinical evidence, descriptive studies or reports of expert committees The Agency for Health Care Policy and Research (AHCPR) 1997

RCTs have not been used a great deal within the fi eld of palliative care.

There are different possible explanations for this, but the nature of pallia-tive care itself may sometimes fi t more readily with research methodologies such as qualitative and descriptive studies. Although tools are available to investigate issues such as quality of life and emotional distress as part of quantitative trials, qualitative research may better assess patient experience (Table 3a.2).

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Table 3a.2 Differences between quantitative and qualitative research Quantitative research Qualitative research

Tests theories Develops theories

Rigid methods Flexible methods

Experiments In depth interviews

Surveys Observation

Large samples Small samples

Numbers Words

Statistics Meaning

Qualitative research

Qualitative research techniques, which are often more suited to palliative care, incorporate the subjective experience that cannot be measured so easily within a mathematical framework. Evidence from qualitative research studies have not been bestowed with the weight of evidence attributed to quantitative research, although the techniques can be as rigorous and are gradually becoming more accepted. Specifi c aims (generic goals) and objectives (specifi c ends or outcomes) and precision and clarity are important whether or not the methodology, data collection and analysis are qualitative or quantitative.

Qualitative research takes account of ways in which the research subject makes sense of his/her individual experience. Ideas and concepts develop as the research progresses, which may then be redirected back to further inform the research fi ndings. Words are used as opposed to numerical data. The method is inductive, to discover new knowledge and to ‘ground’

it into the subjective experience. Although hotly challenged by enthusi-asts of quantitative methodology, qualitative research–which often uses the imaginative expression of language–may have the power to disrupt existing assumptions and to challenge what has been considered as reli-able, factual material.

Qualitative and quantitative research methods can be combined to bring a different perspective and to enhance knowledge in a more holistic way.

A range of techniques, guided by set principles, exist. Techniques include:

1 Observation: Researchers are involved in a fi eldwork setting within, for instance a ward, recording conversations, encounters, non-verbal com-munication, spatial arrangements and physical environment. Aspects such as the quality of care of patients can be explored in this way.

2 Participant observation: Researchers become an active subject within the study group. For instance, they may join in with practical tasks in a ward or day hospice setting with the sole purpose of observing and not infl uencing.

3 Interviews: This is the most widely adopted method within qualita-tive research. Interviews may be interacqualita-tive, with opportunities to develop or deepen the discussion according to the subject in question.

Bereavement research may usefully be conducted in this way.

4 Focus groups: Group interviews have the capacity to generate large amounts of data. Tape-recorded transcripts may be analysed. A number of computer packages exist to sort and code items for analysis which facilitates the handling of large volumes of data. The researcher acts as the facilitator, usually for a group of about eight people. Ideas and experiences can be explored. For instance, a multidisciplinary group of healthcare professionals might explore issues surrounding attitudes to such issues as organ donation at the end of life.

Diffi culties in defi ning study populations

Palliative care covers a very wide range of patients with different mor-bidities. Such patients may include patients with slow growing metastastic cancer who may have many months or even years to live to others with end-stage heart failure and only a few days to live.

For clinical research to be clinically applicable it is important that the research is carried out in relevant patient groups rather than extrapolated from studies, which, although superfi cially similar, may include patients with widely varying characteristics.

Further, many patients with palliative care needs will have signifi cant co-morbidities in addition to their primary illness, which can make defi ning a uniform palliative study population very diffi cult.

Levels of morbidity

A signifi cant proportion of patients with palliative care needs will be unable to adequately report their symptoms or complete questionnaires, either because they are too ill, too fatigued or have a cognitive impairment.

This raises issues of the validity of consent to participate in research. Will consent for today cover consent in a week’s time when the patient’s con-dition deteriorates and they are no longer able to communicate clearly?

Setting appropriate eligibility criteria is crucial and trial design needs to take account of these issues at the outset.

Endpoints and outcomes

Setting appropriate endpoints in palliative care studies can be very dif-fi cult. If these endpoints are not specidif-fi c enough then outcomes will be hard to evaluate. If the endpoints are too specifi c then the trial will be at risk of irrelevance to the complexity of the clinical situation encountered by patients at the end of life. It is very diffi cult to isolate a single variable and monitor its changes over time, particularly in the palliative care popu-lation which is commonly frail and elderly. Furthermore, patients are often receiving multiple interventions for several co-morbid conditions and facing the emotional and spiritual demands of confronting mortality.

A more complex approach is necessary to take account of these different factors and to view interventions in the context of the patient’s overall disease journey.

Recruitment, attrition and compliance

Recruiting patients to trials is diffi cult for many reasons. They are often

‘protected’ by their families and also by clinical staff, who see them as being vulnerable and in need of protection against unnecessary burdens.

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There may be only limited opportunities to approach such patients to discuss trial involvement since rapidly changing clinical and emotional situ-ations may make recruitment inappropriate. The recruitment to trials is therefore often much slower than anticipated.

Once patients are enrolled into studies, sample attrition rates up to 60%

have been recorded due to rapidly changing physical and emotional condi-tions, or even death, during the course of the study.

Compliance can become a particular issue as the disease progresses in terms, for instance, of completing questionnaires. In designing trials which extend into the last weeks of life this needs to be anticipated and other simpler methods of evaluation built into the study from the outset.

Research, audit or service evaluation

There is often much confusion on the differences between research, audit or service evaluation (Table 3a.3) and in particular whether ethical approval is required.

For example, questions are often raised if palliative care patients are interviewed as part of a service evaluation and whether ethical approval is required.

Many clinicians will often approach an ethics committee for clarifi cation.