Are the Results Valid?

Published 27 Feb 2017

The following are the highlights in a study contained in DiCenso, A., Guyatt, G. & Ciliska, D. (2005)The validity of any results in a given study very much depend on whether they yield answers to the research problems highlighted in the hypothesis or research questions. For this particular study, the problem under investigation was to find out if home based intervention for patients with congestive heart failure was effective in prevention or reducing the number of unplanned hospital readmission. Further, the study aimed at finding out if the intervention would improve the quality of life for the patients as well as to investigate whether home based intervention is a means to reducing cost of healthcare incurred as opposed to the norm whereby patients opt for hospitalization. The study established that, the number of those rehabilitated was far much less than those in the control group. It also emerged that the quality of life among those in the intervention group improved after being subjected to home based care. Another interesting finding from the study was that, the cost of health care in home based care was far much low compared to the usual care. Considering that, the study utilized controlled and independent groups to carry out the research provided a great opportunity to come up with valid results which are also replicable. Therefore it is true to say that, the results for this study were valid.

Did intervention and control groups begin the study with a similar prognosis?

Prognosis is the expected course of a disease, and it is important for investigators to ensure that both the control and intervention groups have a similar prognosis right from the onset of the study. Since prognosis predicts the outcome of disease and therefore the future for a patient, how well it is factored in the study design determines the success of the entire study. Patients with Congestive Heart Failure (CHF) have event-full-survival with frequent unplanned readmission to hospital and out of hospital deaths. According to the study, Congestive Heart Failure (CHF) patients experience acute heart failure as well recurrent heart failure.

Question 1.Were patients randomized?

Randomization is a process by which research participants are assigned by chance rather than by choice to their control group ( ). The goal of this process is to produce groups that are comparable in terms of general participant’s characteristics. This ensures that the two groups are as similar as possible at the start of the study so that at the end of the research process, the result can be valid and therefore dependable. Randomization prevents biasness in a study, and the fact that, this study was randomized is a clear pointer towards non-biased results which can be applied in different clinical settings even in other populations other than in the actual study population. In a randomized trial, investigators use a computer program or a table of random numbers to assign each participant to a group. This is important in that it ensures representativeness.
For the purposes of the study patients were randomized. A telephone call was made to an investigator who was unaware of a patients’ demographic and clinical profile. Using a computer generated protocol the investigator allocated an individual to usual care supplemented by home based intervention. This prevents biasness and validates the results of the study in the end.

Question 2. Was randomization concealed?

A concealed randomization refers to a process by which assignment to treatment group is kept unpredictable over the course of a study, usually for purposes of objectivity. Treatment allocation for a participant should not be revealed until they are officially enrolled, as doing so prior to official enrolment could greatly hinder the suitability of certain research subjects. There are two methods used in concealed randomization; use of a central study office that performs the randomization and is telephoned upon participant’s enrollment and secondly use of sequentially numbered, sealed opaque envelopes that contain treatment group assignments.( We can say randomization was concealed because the investigator was unaware of the patient’s demographic or clinical profile and was telephoned to allocate patients to their treatment group.

Question 3.Were patients analyzed in the groups to which they were randomized?

Patients were analyzed in the groups to which they were randomized either in intervention group or usual care group. Endpoint data was compared. Survival curves were used to analyze event-free survival and death. Overall mortality and interaction between treatment mode and other potential co-relates of primary endpoint for both groups was also analyzed. The fact that patients were analyzed in their respective groups was a contributing factor to the attainment of the valid results.

Question 4.Were groups shown to be similar in all known determinants of outcome, or were analyses adjusted for differences?

The groups were shown to be similar in all known determinants of outcome, something which meant that, there was no need for adjusting analyses for differences.
Did intervention and control groups retain a similar prognosis after the study started?
After the study started patients in the intervention group saw a reduction in the number of primary events that led to unplanned readmission in the intervention group were less compared to those in the usual care groups.

Question 5.Were patients aware of group allocation?

The patients were not aware of group allocation but were aware of the study because they signed a written consent in order to participate. Allocation was done by an investigator.

Question 6.Were clinicians aware of group allocation?

The clinicians were not aware of group allocation. The allocation was done by an investigator who was unaware of the patient demographic and clinical file. Clinicians should not be aware of group allocation to avoid bias when caring for patients in the study. This way the end result becomes valid. However, physicians treating patients in the intervention group were aware of their status and may have led to the group getting a more comprehensive medical care.

Question 7.Were outcome assessors aware of group allocation?

The outcome assessors were not aware of group allocation. This is vital in any study so that assessors can analyze the outcome of the study objectively to avoid biased result. In the event where outcome assessors are aware of the group allocation, the results should be declared invalid.

Question 8. Was follow-up complete?

Follow up in a given study is often tasking and time consuming, were discipline lacks, investigators may relent in following up on the study subjects something which can jeopardize the outcome of the study. In this study, follow up was complete as a cardiac nurse made home-visits to patients in intervention group within the target period of 7-14 days. However some patients refused the intervention despite having consented while some had early readmission to hospital. The nurse checked if patients following their prescribed medication as well as counseling patients regarding their sodium intake. Patients were also encouraged to weigh themselves daily. They also contacted primary care physician or cardiologist to review the patients’ clinical status and prescribed treatment. After home visits patients took the initiative to call the cardiac nurse to clarify issues of concern.
Was the intervention delivered and measurement undertaken in a reliable and valid manner?

In a study of this nature, reliability of measurement tools is very central to the success of the study; usually the choice of the measurement tools is determined by the research design and the suitability depending on the sample size. Intervention was delivered as targeted. A cardiac nurse made home visits to patients in the intervention group. The nurse was able to identify signs and symptoms that indicated early clinical deterioration. Adherence to prescribed medication and sodium intake was observed and attended to. Patients were encouraged to weigh themselves to monitor the effect of their overall fluid management. With the intervention the nurse was able to contact primary-care physicians to arrange for a review of patients clinical status as well as prescribed treatment.

Question 9. Was the intervention consistently delivered?

Intervention was delivered in line with the target period. However, before the 7-14 days period initially set to make a home visit after discharge some patients died while others were readmitted to hospital earlier. Incase of readmission before the 6-month period another home visit was arranged for

Question 10. Is there a clear description of the measurement instruments that were used?

For purposes of replicability, the entire study design must be clear and easy to follow. Unfortunately, this is not the case for this study as it is not clear what measurement instruments the research used. In this study, the measurement instruments used are scales and statistics based on the study groups. It is not clear because the results are based on the intervention and usual care groups.

Question 11.Were the measurement instruments used in a valid and reliable manner?

Scales and statistics measured what they were supposed to measure accurately. The variables that were being measured included: endpoints, quality of life and healthcare cost and the measurement instruments were the most suitable in measuring such variables.

What are the results?

The findings that the cost of home based care is still a viable alternative and option is worth commenting. Equally important is the finding that, home based care is very popular and can succeed when applied carefully. A quantitative method was used and this proved a success and a strong attribute for this research. The study established that, the number of those rehabilitated was far much less than those in the control group. It also emerged that the quality of life among those in the intervention group improved after being subjected to home based care. Another interesting finding from the study was that, the cost of health care in home based care was far much low compared to the usual care.

Question 12. How large was the intervention effect?

The intervention affected the number of readmissions in hospitals monthly and recurrent hospital admissions. Those receiving intervention were less likely to be hospitalized. Healthcare costs were low in the intervention group. The cardiac nurse was able to give accurate information about a patient to the primary care physician and these enable the physician to provide better care for the patient. Patients were also more aware of their illness and put in a position to manage it. The intervention had a great impact on the patient.

Question 13.How precise was the estimate of the intervention effect?

The intervention effect was precise because the outcome of the study was based on the actual number of patients both in the intervention group and the usual-care group.
How can I apply the results to patient care?
The results are clear indication that, home based care, although still unpopular is very effective. Therefore, I would advocate for the adaptation of home based care alongside the traditional healthcare system. My decision would be based on research findings which support the type of healthcare as being effective, less expensive as well as easy to apply.

Question 14.Were the study patients similar to the patients in my clinical setting?

Patients in the study are similar to those in my clinical setting. The patients in my clinical setting have the same prognosis and conditions with those who have (Congestive Heart Failure). CHF.This makes the study findings very applicable to my clinical setting. The fact that patients in my setting are in very big way same as those in the study also means that, the findings can contribute in advancing the quality of healthcare provision especially if the administration can be wiling to adapt the result and design policies informed by this particular study findings.

Question 15.Were all important outcomes considered?

Important outcomes in this study were considered. These includes: endpoints, quality of life and healthcare expenditure. Out of hospital deaths and unplanned readmissions were noted to have reduced in the intervention group. Healthcare expenditure as well as the quality of life was also considered and it was noted that the quality of life improved.

Question 16.Are the likely intervention benefits worth the potential harm and costs?

From the study the intervention benefits are worth. The hospital costs were less compared to the usual care group. Patients are better cared for by their physicians because they are made aware of how a patient responds to certain treatment. Patients are more knowledgeable about their illness and are more able to manage it by adhering to prescribed medication, observing sodium intakes and weighing themselves to monitor the effect of their overall fluid management. The potential harm in intervention is very minimal if any exist because the study findings did not show any harm. Given that the cost of home based care appears to be far much lower than traditional healthcare, it seems appropriate for healthcare practitioners to consider incorporating the system in mainstream healthcare provision. Despite the attractiveness of the home based care, its success will as a matter of fact depend on the willingness of all stakeholders in the health sector to work together in promoting its wide application. There is therefore a need for more research in this area so as to give credence to the findings of this particular study or where applicable to make corrections and offer alternatives. Future studies must set out to investigate how different forms of healthcare can be integrated in order to come up with an overall best practice system. There is however a need to avoid discrediting traditional or conventional healthcare systems which have for a very long time been used and are responsible in part, for the progress in healthcare the nation enjoys. All other strategies should only compliment the existing healthcare systems.


  • DiCenso, A., Guyatt, G. & Ciliska, D. (2005). Evidence based nursing: A guide to clinical practice. Philadelphia: Mosby.
  • Accessed on 20.08.2007.
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