INTRODUCTION:

In the current climate of expectations of a medical practice, increased consumer awareness and ready access to the internet, service users are increasingly critical of the care and treatment they receive. Obstetric and maternity care are no exception .offering evidence based medicine and health care is important mainly for two reasons. Firstly, health care practitioners who would like to maintain a critical approach to their practice need to understand the strength of the evidence supporting any treatment or intervention they advise. Secondly, women accessing care want to evaluate for themselves the value of any suggested treatment rather than taking the advice on trust.^1,2

EBP requires an awareness that care affects a constellation of important outcomes, ranging from the physical and emotional, personal and family integrity, to the wider social and economic. Finding and understanding evidence to inform decisions and choices about care will mean confronting uncertainty about what is best, or better, and dealing with frustration when the usefulness of evidence may not be straightforward.⁷

Definition:

EBP means that midwives often find themselves questioning longstanding routines in systems that are not easy to challenge. Effective questioning demands accumulating convincing evidence about what is likely to be effective care, developing effective skills to assemble and evaluate evidence, and then using it to change practice for the better.³

‘Evidence –based health care’ has been important in helping health care professionals and others, including policy makers and managers, and understand that research is carried out so that the results it yields can be used. – Gray 1997⁴

EBP requires active searching for, and appraisal of, research evidence to inform decisions about tests, treatments, patterns of practice, and policy.⁴

EB clinical practice as the ‘judicious use of the best evidence available so that the clinician and the patient arrive at the best decisions, taking into account the needs and values of the individual patient’. ⁴

Aspects of EBP in midwifery:

The most challenging aspect of practising evidence-based midwifery:

The need to weigh up the validity

Applicability of evidence about potential benefits and risks of certain choices and decisions whilst maintaining open and honest communication with women, families and colleagues.⁴

Fundamental questions in evidence based midwifery:

1. Is what I intend to do more good than harm?

2. Am I spending my time doing the right things?

Every midwife can develop key skill to ask these questions, work through the answers and apply new learning, knowledge and insights effectively in her or his practice. ⁷

Evaluating and assessing the effectiveness of care:

Effectiveness means a measure of the extent to which a specific intervention, procedure, regimen, or service, when deployed in the field in routine circumstances, does what it is intended to do for a specific population.

Ex. Well intentioned treatment – in this case the administration of high concentration of O₂ to premature babies – which had unknown and unsuspected consequences. This regimen results in blindness. This unintended harm could have been minimized if practitioners who advocated the use of high concentration oxygen had been committed to asking questions about effectiveness.³

One of the difficulties about the term effectiveness is that it is understood differently by different people.

For example, imagine a policy of routine augmentation of labour is introduced for a trial period in local labour ward to duce the length of time women spend in labour care and that the effectiveness of the policy was measured after six months. The results of the evaluation show a reduction in the time women spent in labour care and therefore it is proposed that the policy be adopted. However, the midwife responsible for collating unit statistics points out that the compared to the 6 months period previous to the introduction of the new policy, there has been a high rate of analgesia use and a high proportion of women have said they were dissatisfied with their experience of labour. This would suggest that measuring effectiveness using length of labour alone is inadequate and that adopting the policy would be unjustified as it could be associated with more harm than good.

As this example demonstrates, judgments about the effects of care during pregnancy and child birth, as in other areas, are neither value free nor situation free. ³

Evidence based care:

Evidence should be used to inform decisions in a number of areas:

Policy, guidelines for practice , the appropriate organization of care , public health decisions , clinical decisions and information to help women’s choice , health promotion and education for parenting.

Ways of using evidence in practice and describe the sources of information used to inform decisions about care.

These are

· Individual values or preferences

· The clinical examination

· Research evidence

· The context of care ⁷

Five steps for the use of evidence in practice are described:

1. Finding out what is important to the women and her family

2. Using information from the clinical examination

3. Seeking and assessing evidence to inform decision

4. Talking it through

5. Reflecting on outcomes, feelings and consequences. ⁷

Process of using evidence in practice:

· Framing clear and relevant questions that will lead to an effective search

· Planning an efficient search to answer the questions

· Assessing and weighing up the evidence.¹¹

Framing clear questions:

Principles of good questions

The right and best evidence is the ability to convert a precise, yet possibly vaguely expressed, need into an answerable, focused, structured questions.

Well-structured questioner has four components:

Population – in the case of midwifery, women

Intervention – cause, prognostic factor, treatment.

Comparison – control or comparative interventions

Outcome – ways in which the interventions effect is measured.

An additional component relating to study design can also be employed, and prove particularly helpful when improving the efficiency of a search .¹¹

The most useful types of study design that may form part of a search include:

a. systematic reviews- literature reviews focused on a single question which identify , appraise and synthesize all relevant high quality research evidence.

b. meta analyses – systematic reviews or overviews which employ quantitative methods to summarize the result .

c. Randomized controlled trials – patients are randomized into intervention and control groups, followed ups for outcomes.

d. Cohort studies- identifications of two groups (cohorts) , one of which normally received exposure to an intervention and one which did not , followed up for outcomes .

e. Case series – reports on a series of patients with outcomes.

Consider the quality of study design – the number of patients treated, or group size the duration of the study; the objective measurement of outcomes; and elimination of bias .⁹

To assist the understanding and application of PICO to the midwifery setting.

Assessing and interpretating the evidence:

There are several accessible books that detail structured approaches to assessing research reports. An essential step in assessing the evidence is to discard poor quality or irrelevant reports. Three preliminary and basic questions as a way of getting an orientation to the paper are:

1. Why was the study done, what were the hypotheses, and what were the authors testing?

2. What type of study was carried out?

3. Was this research appropriate to the broad field of research studied?

Propose the following questions to assess evidence:

· Is it true( validity)

· Are the valid results important?

· Does it apply to the women / woman in my care?¹³

VALIDITY:

When reviewing evidence from a study both internal and external validity of the results need to be considered.

· Validity: the degree to which the inference drawn from a study, especially generalizations extending beyond the study sample, are warranted when account is taken of the study methods, the representativeness of the study sample, and the nature of the population from which it is drawn.

· Internal validity: is concerned with whether selection of groups and theway comparisons were carried out between the study’s groups were sufficiently robust so that any reported difference is likely to be attributable to the effect being measured.

· External validity: is concerned with the extent to which research findings can be generalized to people who are similar to the participants but who did not take part in the study.

A fundamental point when assessing evidence, and the validity of a study, is to question whether the methodology used is appropriate to the question posed

Most research studies are concerned with one or more of the following:

I. Therapy- testing the efficacy of drug treatments, surgical procedures, alternative methods of service delivery, or other interventions. Preferred study design is randomized controlled trial.

II. Diagnosis- demonstrating whether a new diagnostic test is valid and reliable. Preferred study design is cross sectional survey … in which both the new test and the gold standard test performed.

III. Screening- demonstrating the value of tests that can be applied to large populations and that pick up disease at a pre symptomatic stage. Preferred study design is cross sectional survey .

IV. Prognosis – determine what is likely to happen to someone whose disease is picked up at an early stage. Preferred study design is longitudinal cohort study.

V. Causation – determining whether a putative harmful agent, such as environmental pollution, is related to the development of illness. Preferred study design is cohort or case control study, depending on how rare the disease is … But case reports. May also provide crucial information.

Importance:

Assessment of importance is related to the

· size and potential benefits of the effects measured in a study;

· probability of outcomes occurring over time

· Strength of association between the outcomes and interventions

· Increased probability of particular outcomes in different groups

· Precision of the estimates of effect.

Established methods are applied to numerical data reported in a study which are used to assess the importance of the results. Describe the method to calculate how many people need to be treated to avoid an adverse outcome (number needed to treat; NNT) OR to harm one person (number needed to harm; NNH). Measures of importance, strength of associations and precision include relative risks, absolute risk reduction, number needed to treat NNT, and number needed to harm NNH, odds, odds ratios and confidential intervals.

· Odds- a ratio of non-events to events. Ex. 9:1

· Odds ratio OR – is the odds of having the target disorder in the experimental group relative to the odds in favour of having the target disorder in the control group or the odds of being exposed in subject with the target disorder divided by the odds in favour of being exposed in control subjects .

· Risk ratio RR – is the ratio of risk in the treated group EER to the risk in the control group CER , RR= ERR/ CER.

· Relative risk reduction RRR – the proportional reduction in rates of bad outcomes between experimental and control groups .

· Absolute risk reduction ARR – the absolute arithmetic difference in rates of bad outcomes between experimental and control group.

· Number needed to treat NNT – the number of patients who needed to treated to achieve one additional favourable outcome, calculated as 1/ ARR and accompanied by a 95% confidence interval.

· Number needed to harm – the number of patients who need to be treated to achieve one additional unfavourable outcome , calculated as 1/ ARR and accompanied by a 95% CI

· CI – express the range within which we would expect the true value of a statistical measure to fall.¹³

Appraising evidence for validity and importance

The assessment of the validity of particular studies will depend on the type of evidence used. Propose the following categories:

1. Diagnosis

2. Prognosis

3. Harm

4. Therapy

5. Systematic reviews

6. Decision analysis

7. Qualitative research ¹²

1. Diagnosis:

One of the most rapidly changing fields of maternity care lies in diagnosis and screening, particularly during the antenatal period. Midwives should be able to appraise current evidence and convey the accuracy of results to the women and families in their care. The following questions to appraise to appreciate a paper or systematic review on diagnosis:

1. Was there an independent, blind comparison with a reference ‘gold’ standard of diagnosis ?

2. Was the diagnostic test evaluated in an appropriate spectrum of patients?

3. Was the reference standard applied regardless of the diagnostic test result ?

4. Was there an independent, blind comparison with a reference ‘gold’ standard of diagnosis ?

Two criteria should have been met in order to answer this question in the affirmative.

First, the women or babies in the study should have undergone both the diagnostic test (ex. nuchal fold scanning for Down syndrome) and the reference (gold) standard testing e.g. amniocentesis for Down syndrome.

Second, the person interpreting the tests of one should not know the results of the other, otherwise, consciously or subconsciously , the , the interpretation might be biased.

Was the diagnostic test evaluated in an appropriate spectrum of patients?

For example, if you are asking a question about the use of nuchal fold testing in all age groups of women , you want it to be tested in a population of all age groups of women.

Was the reference standard applied regardless of the diagnostic test result ?

When patients have a negative diagnostic test result, investigators are tempted to forego applying the reference standard, and when the Latter is invasive , it may be considered inappropriate to do so . If the reports fails one or more of these criteria, you may wish to keep searching sources for further evidence.

Is this evidence about a diagnostic test important ?

Once have decided on the validity of the report or reports, it is appropriate to ask whether the evidence is important. This includes assessment of the prior assessment of the possibilities before carrying out the test prior or pre-test probabilities and the ability of the test to distinguish patients with and without the target disorder sensitivity and specificity, and likelihood ratios.

Once determined the validity and importance, the following questions help to determine whether or not you can apply this valid, important evidence to women and families in your care

Is the diagnostic test available, affordable , accurate , precise in your setting ?

Can you generate a clinically sensible estimate of your patients pre test probability ( from practice data , from personal experience , from the report itself , or from clinical speculation )?

Will the resulting post test probabilities affect your management and help your patient?

Could it move you across a test treatment threshold ? Would your patient be a willing partner in carrying it out ?

Would the consequences of the test help your patient?^12,10

2. PROGNOSIS/ RISK ESTIMATION:

Is this question about prognosis valid?

In assessing evidence related to prognosis for validity , we need to ask

1. Was a defined, representative sample of patients (women/ foetus/ babies) assembled at a common point in the course of their pregnancy?

2. was follow up of participants sufficiently long and complete?

3. were objective outcome criteria applied in a blind fashion?

4. if subgroups with different prognoses are identified

was there adjustment for important prognostic factors ?

was there validation in an independent group of test set patients^9,12

HARM:

Is this evidence about harm valid?

Propose the following questions to assess the validity of studies to

Evaluate the possibility of harm:

1 were there clearly defined groups of patients, similar in all important ways other than exposure to the treatment or other cause?

2. Were treatment exposures and clinical outcomes measured the same ways in both groups?

3. Was the follow up of study patients complete and long enough?

4. Do the results satisfy some diagnostic tests for causation?

§ Is it clear that the exposure preceded the onset of the outcome?

§ Is there a dose response gradient ?

§ Is there positive evidence from challenge re challenge study?

§ Is the association consistent from study to study?

§ Does the association make biological sense?

5 Are the valid results from this harm study important?

6. Can the study result be extrapolated to your patient? ⁹

3.THERAPY:

There are so many factors that might influence the outcome of treatment that the only good way to control for possible sources of bias is to allocate people randomly to different treatment conditions.

Before going on to assess the results of a study, one must first ask the following questions

1. Are the result of this single study valid?

The key question to answer, following are:

A. Was the assignment of patients to treatments randomized?

B. And was the randomization list concealed?

C. Were patients and clinicians kept blind to which treatment was being received?

D. Aside from the experimental treatment, were the groups treated equally?

E. Were the groups similar at the start of the trial?

2. Are the results of this single preventive or therapeutic trial important?⁹

Systematic review and system analysis:

A systemic review is a review that includes explicit and detailed description of why and how it was conducted so that it should be possible to replicate it.

Meta-analysis is a method of combining statistically the results of independent research studies, which are sufficiently similar, to generate a single estimate of effect for a particular treatment or therapy.

Propose the following questions to test the validity of a systematic review:

1. Is it an overview of RCT s of the treatment you are interested in?

2 Does it include a methods section that describes?

a. Finding and including all relevant trials?

b. Assessing their individual validity?

c. Were the result consistent from study to study?

Does it includes a methods section that describes finding and including all the relevant trials ?

assessing their individual validity?

A. Were the results consistent from study to study?

B. Are the results of this systematic review important?

· Is your patient so different from those in the overview that its results can’t help you?

· How great would the potential benefits of therapy actually be for your individual patient

· Do your patients and you have a clear assessment of their values and preferences?

· Are they met by this regimen and its consequences? ^{6, 9}

Assessing the qualitative research:

The aim of qualitative research as being ‘ to study things in their natural setting, attempting to make sense of, or interpret, phenomena in terms of the meaning that people bring to them’, and that researchers use a holistic perspectives which preserves the complexity of human behaviour.

The contribution of social science and anthropology in researching maternity care is immense and provides a mine of information regarding the perspectives of child bearing women using the maternity services and their experiences, to inform midwives who want to understand better and improve care.⁵

The following questions for assessing qualitative research are

1. Did the paper describe an important clinical problem examined thoroughly a clearly formulated questions?

2. Was a qualitative approach appropriate?

3. How were the setting and subjects selected?

4. What was the researchers’ view and has this been taken into account?

5. What methods did the researcher use for collecting data, and are these described in enough detail?

6. What methods did the researcher use to analyse the data, and what quality control measures were implemented?

7. Are the results credible?

8. What conclusions were drawn , and were they justified by the result ?^{10, 12,13}

REFERENCES:

1. James D , Mohamed K, Stone P, van Wijngaarden W, Hill LM , Evidence Based Obstetrics , Saunders, Amsterdam, 2003.

2. Guy’s and St Thomas’ Hospital NHS Trust (GSTT), Maternity Guidelines, women’s health directorate. GSTT, London.

3. Chalmers I, Enkin M E, Kierse MJNC, Effective care in pregnancy and childbirth, Oxford University Press, Oxford, 1989.

4. Gray J A Muir, Evidence Based Health Care: how to make health policy and management decisions. Churchill Livingstone, Edinburgh.

5. Mays N, Pope C, Qualitative research in health care. BMJ Publishing Group, London .

6. Jahad J Randomized Controlled Trials. BMJ, London.

7. Page L Using evidence to inform practice. In: Page L ed: the new midwifery science and sensitivity in practice. Churchill Livingstone, London.

8. Smith B, Darzins P, Quinn M, Heller RF Modern methods of searching the medical literature. Medical Journal of Australia 1992, 157: 603 -611.

9. Stratus ES, Scott Richardson W, Glasziou P, Haynes RB, Evidence based medicine: how to teach and practise EBM, 3^rd edition, Elsevier, Edinburgh.

10. University of Oxford, Manual of Oxford workshop on teaching evidence based medicine. University of Oxford, Oxford.

11. Rosenberg W, Donald An Evidence –based medicine: an approach to clinical problem –solving. British Medical Journal 1995, 310: 1122-1125.

12. Sackett D L, Richarson WS, Rosenberg W, Haynes B R, Evidence based medicine: how to practise and teach EBM. Churchill Livingstone, Edinburgh Greenhalgh T, How to read a paper: basics of evidence – based medicine. BMJ Publishing Group, London.

Received on 23.12.2015 Modified on 29.01.2016

Int. J. Adv. Nur. Management. 2016; 4(3): 376-382.

DOI: 10.5958/2454-2660.2016.00067.3

Women or problem	Intervention (cause, prognostic factor, treatment)	Comparison intervention If necessary	Outcomes
How would I best describe a group of women similar to mine	Which main intervention or complication or risks factor am I Considering?	What is the probability of adverse outcome?	What can I hope to accomplish? What else would be affected?
In women in early pregnancy who are vomiting most of the day?	Acupressure	No Acupressure	Acupressure leads to a reduction of vomiting and the experience of nausea
In women without other complication	Who are grand multiparas	When compared with women who are less than Gravida 5	Is there a greater probability of excessive bleeding, need for blood transfusion, illness or death?
In women of 26 years of age	Who have an amniocentesis for the diagnosis of Down’s syndrome	Who have not had amniocentesis for the diagnosis of Down’s syndrome	What is the probability of miscarriage? What is the probability of Down syndrome? What are the sensitivity and specificity of the test?
In nulliparous women without complications	Who have an elective prelabour caesarean section	Rather than allowing labour and vaginal birth	What will the effect on perinatal mortality and morbidity and maternal mortality and morbidity be?
In pregnant women	Who are over 40 years old	Compared with women of under 40 years of age.	Is there a greater probability of adverse outcomes ( e.g perinatal mortality and higher intervention rates as a result of age alone ? ¹²