Assessing the quality of a published research study Essay Example

  • Category:
  • Document type:
    Research Paper
  • Level:
  • Page:
  • Words:

Critical Appraisal of a Published Research Study 10


University/ College Name

Study Purpose

No. The aim of the research was not clearly stated.

Purpose of the study. The study sought to compare two debridement techniques in terms of the duration taken to achieve sufficient “debridement of venous (VLU) or mixed arterial/venous (MLU) leg ulcers” (Mudge et al. 2013, p. 44). The two techniques used were larval therapy dressing and the standard technique utilizing hydrogel. However, Mudge et al. did not clearly state whether it was an equivalence or a superiority study. Neither was there any null or alternative hypothesis (Chan 2003, p. 172).

Application to nursing practice. The study is significant to nursing practice as its outcome serves to fortify the limited findings on the effectiveness of larval therapy in wound debridement. This will be paramount in wound care as larval therapy may be extended to treat other varieties of wounds such as necrotizing fasciitis, primary burns, traumatic necrotic leg wounds, pressure sores and other intractable wounds (Lagan & Parnes 2007, p. 489). Since wound care management is a role commonly played by nurses, the study will augment the widely advocated evidence-based practice and care especially in setups where qualified personnel to perform surgical removal of slough are limited.


If relevant background literature was reviewed. No. Not sufficient relevant literature was reviewed. Mudge et al. (2013, p. 43) asserts that as of the time when the study was done, there was no existing randomized controlled trial (RCT) study that supported a specific method of debriding wounds. The assertion appears to be an affirmative statement from the researchers but on a quick google search on larval wound debridement, a number of peer-reviewed RCT articles such as Turkmen, Graham & McGrouther’s (2010, pp. 184-188) “therapeutic applications of the larvae for wound debridement” and Soares et al.’s (2009, p.1) are available whose outcomes supported the effectiveness of larval therapy over use of hydrogel in wound debridement. However, the latter study suggested larval therapy to be costlier.

Justification for the study. The study was justified since there is a need to substantiate available evidence on the effectiveness of larval therapy in wound debridement. The outcome of the study also increased confidence in the applicability and validity of previous research on wound debridement using larval therapy (Young & Solomon 2008, p. 83).

Design (RCT)

Description of the study design. The study design was a randomized single blind controlled trial. The researchers presented demographic data to enhance obtaining baseline equivalent groups on randomization. Subjects were stratified and randomized to either hydrogel or larval therapy group (Mudge et al., 2013, p. 44). Ulcers chosen for the study had to contain at least 25% slough occupying an area of more than 2 cm2 and, if there was another nearby ulcer, it was to be at least 5cm away. Assessors of the level of wound debridement were blinded to avoid subjective outcomes. However, Mudge et al. (2013) did not fully describe the stratified randomization. They did not comprehensively identify specific covariates such as age, sex and probable cause of the wound before stratifying combinations of these covariates into blocks and assigning subjects to the blocks (Suresh 2011, p. 9). The fact that these covariates were not identified in the study design, but they featured in the results may have introduced confounding factors that may have led to a systematic bias. Furthermore, the allocation of interventions by Mudge at al. (2013, 44-45) seem not to have been concealed as it is not mentioned in the study method and design.

Appropriateness of the design for the study questions. The study design, RCT, was appropriate for the aims of the research. Since the study was to answer questions about effectiveness of an intervention, the individual RCT design used provided robust evidence. The evidence obtained was meant to augment allegations and the limited existing evidence on the effectiveness of larval therapy dressings in the removal of necrotic tissue in wounds. The study outcome supports the use of larval therapy even though other considerations such as the cost implications of using larval therapy over hydrogel was not factored in the study. If the costs had been considered then comprehensive questions about effectiveness of the therapy and the financial implications of its applicability in a clinical set-up would have been answered.

Biases. Systematic bias may have occurred and may have resulted in an overestimation of the truth about the study outcome. Even though the observers were blinded, the subjects were not blinded, and their selection was based on an estimate of a previous assumption leading to unequal allocation of subjects to interventions (Mudge et al. 2013, p. 44). Consequently, larval therapy intervention had more subjects allocated to it than subjects allocated to hydrogel. Since this disparity in allocation was based on a previous study whose outcome was in favor of larval therapy over hydrogel in wound debridement, the researchers seemed to have an inclined pre-formed idea of the outcome of their study. Therefore, this confounding factor places doubt on the outcome of the study presented by Mudge et al. (2013, pp. 45-48).

Sample number = 88 subjects

No. The sample was not exhaustively described. Mudge et al. (2013, p. 44) did not include significant details of the sample such as age and sex of participants even though they described these demographic characteristics in the results. This means that the researchers did not initially deem these demographic variables to be of significance until they obtained their results.

If the sample size was justified? Yes, it was justified.


Persons involved. The study sample consisted of people with either VLU or MLU (Mudge et al. 2013, p. 44).

Characteristics. The ulcers had to contain more than 25% necrotic material with a brachial pressure index of at least 0.5mmHg (Mudge et al. 2013, p. 44).

How sampling was done. Identification and recruitment of the subjects was via community leg ulcer clinics, hospital outpatient and inpatient visits and admission, and via community nurse caseloads

Two groups were involved in the study. One group consisted of patients with VLU while the other group had patients with MLU. The two groups used in the research were similar in terms of «a brachial pressure index «of at least 0.5mmHg and an allowed size of slough – more than 25 (Mudge et al. 2013, p. 44).

Obtainment of if informed consent. Yes, it was obtained (Mudge et al. 2013, p. 44).

Ethics approval. The study was ethically approved as stated by Mudge et al. (2013, p.45). The researchers sought permission “from Oxfordshire Indepenent Research Ethics Committee” and from other “local research and development departments” (Mudge et al. 2013, p.45). Subjects participated voluntarily. The study was also conducted as per the regulations and guidelines of the “world medical association Declaration of Helsinki Ethical Principles for Medical Research Involving Human Subjects (52nd WMA General Assembly, Edinburgh, Scotland, October 2000), the Good Clinical Practice Consolidated Guideline approved by ICH and Sis 1031 (2004), 1928 (2006)” (Mudge et al. 2013, p, 45).


Reliability of outcome measures. Yes, they were reliable.

Validity of outcome measures. Yes, they were valid. The main outcome measure was the time to achieve complete debridement. At complete debridement, the wound bed had to be clean enough not to require a debriding agent (Mudge et al. 2013, p. 44). A maximum period of 21 days was allowed for ascertaining debridement that was a justifiable duration of assessing debridement.

Frequency of measuring outcomes. Outcome measures were reviewed after every 3-4 days till either intervention exhibited complete debridement or up to the 21 day of assessment whichever came earlier. After the 21 days, the subjects on the two interventions were evaluated for a further 7-14 days to determine the occurrence of re-sloughing.

Outcome areas. Among the outcome measures used by Mudge et al. (2013, pp. 46, 47) include wound malodor, granulation, sloughing, amount of exudate, the condition of periulcer skin and ulcer-related pain.

Measures used. Wound malodor was ascertained by smelling the presence or absence of wound odor (Mudge et al. 2013, p. 47). Slough percentage was classified into two: 25-50% slough and more than 50% slough although the researchers did not clarify what they used to measure these percentages. Percentage of granulation was also classified into two: 0-50% and more than 50% granulation. Exudate was classified as absent, minimal, moderate, heavy or copious. Periulcer condition was categorized as healthy, erythematous, macerated, eczematous and other. The latter included dry and flaky, atrophy blanche, hemosiderin containing, edematous and scaring (Mudge et al. 2013, p. 47). Ulcer related pain was assessed using a visual analog scale that was self-administered.


If the intervention was described in detail. Yes, it was a detailed description since Mudge et al. (2013, pp.43, 44) described the larval therapy dressing including its manufactures and postulated mechanism of action.

Avoidance of contamination. Not addressed.

Avoidance of co-intervention. Yes, there was no described co-intervention.

Description of intervention. The intervention studied entailed the use of a BioFOAM larval therapy dressing in wound debridement (Mudge et al. 2013, p. 43). The intervention was delivered by nurses in 2-7 intervention phases after every 3-4 days when subjects visited for a review of the progress of the study intervention.

Replication of the intervention to nursing practice. Yes, the intervention can be used in nursing practice since it was found to be effective in wound debridement, and a majority of nurses who implemented the intervention during the study found it easy to apply and remove during treatment (Mudge et al. 2013, p. 48).

Reporting of the results in terms of statistical significance. Yes, the results were reported in terms of p values.

Method of data analysis used was stated. Analysis was conducted on an “intention-to-treat” basis utilizing “the last value carried forward method” (Mudge et al. 2013, p. 44).

Reporting of clinical importance. Yes (Mudge et al. 2013, p. 45).

The results and if they were statistically significance. The results obtained showed that larval therapy dressing debrided wounds for a shorter time compared to hydrogel. Within the 21 days, 67.4% of ulcers from the larval arm had been fully debrided compared to 26.2% from the hydrogel arm based on an ‘intention to treat’ (Mudge et al. 2013, p. 45). These results were statistically significance with a p value equal to 0.001(p=0.001) (Mudge et al. 2013, p.45).

Results’ clinical importance. The results suggest that larval therapy dressings can be effectively used as an alternative method of wound debridement.

The clinical significance of differences between groups. The statistical significance of the outcome of wound debridement between the two interventions suggest that larval therapy dressing is equally as effective as the standard wound debridement technique that utilizes hydrogel.


Reporting of withdrawals and drop-outs. Yes, it was reported.

Reasons for dropouts or withdrawal adequately explained. Yes. Out of 88 subjects recruited, 26 were withdrawn mostly due to infection, increased slough, pain or discomfort (Mudge et al. 2013, p. 45). Three patients in the larvae group also withdrew after they requested removal of the dressing and discontinuation of treatment.

Study Conclusions

If presentation of conclusions was done. No.

Study conclusion. Mudge et al. (2013, pp. 43-51) did not conclude the study although they discussed their findings.

Implications of the results for patient care and/or nursing practice. The results suggest that larval therapy dressings can be an effective alternative method of wound debridement in set ups where surgical wound debridement may not be reliable due to insufficiency of qualified personnel.


The study was a randomized controlled multicenter study to ascertain the effectiveness of larval therapy dressings in wound debridement in comparison to a standard debridement technique that utilizes hydrogel. The randomization prevented selection and accidental bias in the study. However, the researchers did not describe the randomization sufficiently nor did they incorporate other covariates such as age and sex in their randomization. Considering the size of the clinical research, covariate adaptive randomization would have been a valid alternative technique for randomizing the subjects (Suresh 2011, p. 10). Nevertheless, the results obtained in the study adds onto the existing evidence that larval therapy can be effective in wound debridement. Applicability of the results outcome in a clinical setup may require further equivalence research that would incorporate the costs of larval therapy dressing intervention over the use of standard hydrogel. Therefore, the research is of average quality.

How the appraisal has impacted on my understanding of assessment of published research. I have understood the basics of assessing the quality of published research such as RCT. First is to identify if a research addresses a distinctly focused issue. Then the randomized allocation of subjects to interventions has to be clearly stated and demonstrated. All subjects in the trial have to be accounted for elaborately. Blinding of subjects and personnel assessing the interventions enhances credibility of outcomes. Groups assigned to interventions should be similar and treated equally except with the intervention under study. The treatment outcomes should be well reported, and their statistical significance shown. If an RCT research meets these criteria, then it shall be of sufficient quality to enhance its reliability (Godin, Dhillon & Bhandari 2011, p.195).

Reference List

Chan, YH, 2003, Randomized controlled trials (RCTs)-Sample size: The magic number?, Singapore Medical Journal, vol. 44, no. 4, pp. 172-174.

Godin, K, Dhillon, M & Bhandari, M 2011, The three-minute appraisal of a randomised trial, Indian Journal of Orthopaedics, vol. 45, no. 3, pp. 194-196.

Mudge, E, Price, P, Neal, W & Harding, KG 2013, A randomised controlled trial of larval therapy for the debridement of leg ulcers: Results of a multicenter, randomized, controlled, open, observer blind, parallel group study, Wound Repair and Regeneration, vol. 22, pp. 43-51.

Parnes, A & Lagan, KM 2007, Larval therapy in wound management: A Review, International Journal of Clinical Practice, vol. 61, no. 3, pp. 488-493.

Soares, MO, Iglesias, CP, Bland, M, Cullum, N, Dumville, JC, Nelson, EA, Torgerson, DJ & Worthy, G 2009, Cost effectiveness analysis of larval therapy for legs. British Medical Journal, vol. 338, no. b825, pp. 1-8.

Suresh, KP, 2011, An overview of randomization techniques: An unbiased assessmnent of outcome in clinical research. Journal of Human Reproductive Sciences, vol. 4, no. 1, pp. 8-11.

Turkmen, A, Graham, K & McGrouther, DA ,2010. Therapeutic applications of the larvae for wound debridement. Journal of Plastic, Reconstruction & Aesthetic Surgery, vol. 63, no. 1, pp. 184-8.

Young, JM & Solomon, MJ 2009, How to critically appraise an article. Nature Clinical Practice Gastroenterology & Hepatology, vol. 6, no. 2, pp. 82-91.