Improving cardiopulmonary resuscitation skills retention: effect of two ...

Resuscitation 34 (1997) 221 – 225

Improving cardiopulmonary resuscitation skills retention: effect of two checklists designed to prompt correct performance Phillip Ward a,*, Lisa A. Johnson b, Neil W. Mulligan c, Marie C. Ward d, Diana L. Jones b a

Department of Health and Human Performance, 247 Mabel Lee Hall, Uni6ersity of Nebraska-Lincoln, Lincoln, NE 68588 -0229, USA Department of Physical Education, Health and Recreation, 101 McCormic Hall, Illinois State Uni6ersity, Normal, IL 61790 -5121, USA c Department of Psychology, Campus Box 4620, Illinois State Uni6ersity, Normal, IL 61790 -4620, USA d Ser6ices for Students with Disabilities, 132 Canfield Administration Building, Uni6ersity of Nebraska-Lincoln, Lincoln, NE 685588 -0401, USA b

Received 29 May 1996; received in revised form 29 October 1996; accepted 29 October 1996

Abstract Previous research has shown that regardless of an individual’s experience, life support skills such as cardiopulmonary resuscitation (CPR) are poorly performed as soon as 1 month following training. The purpose of this study was to compare the effects of two checklists designed to prompt correct CPR performance. We compared the performance of 169 undergraduate students, at the time of course assessment, with retention testing that occurred 2 months following the course assessment. Students were randomly assigned to a control group, a short version of a CPR checklist and a longer more detailed version. Two groups of variables were created: procedural and compression – ventilation variables. In addition, an overall-performance variable was created, summarizing performance on the procedural variables. Binary variables were assessed with x 2-tests of independence. One-way ANOVAs, using ‘group’ as the between-subjects factor, were used to assess each continuous variable. Comparisons between groups yielded significant differences of P B 0.05. The long checklist generally led to superior performance on the procedural variables. The results support the hypothesis that remembering the steps of CPR is too complex for some. Though preliminary, the findings of this study indicate that the detailed checklist was an effective strategy to improve the post-course performance of CPR. © 1997 Elsevier Science Ireland Ltd. Keywords: Cardiopulmonary resuscitation; Checklist; Retention; Training

1. Introduction In 1973, the American Heart Association and later the American Red Cross (ARC), recognizing that often the first people on the scene of emergencies were lay persons and not medical personnel, proposed and pursued a policy of training the lay public in basic life support skills. The goal of this policy has been to increase the number of persons trained to perform basic life support skills and increasing the number of lives saved by emergency intervention [1]. Since 1975, 35 studies have been published documenting the effectiveness of the training and retention of cardiopulmonary * Corresponding author. E-mail: [email protected]

resuscitation (CPR) skills [2,3]. A review of these studies reveals two recurring problems, poor training in CPR at the basic life support skills course and poor retention of CPR during the months following the course [2,3]. These problems have typically been addressed by improving the course design using alternatives such as computers and videodisc [4], modified courses [5], and self paced instruction [6]. To date these efforts have not improved retention. One conclusion from the retention studies is that perhaps remembering the steps of CPR is too difficult a task. Some have argued in favor of simplifying the procedures so that lay public might remember them [2]. An alternative strategy to simplifying the procedures of basic life support skills is to use a checklist to take the

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guess work out of the procedures. Checklists have been used to more effectively train course participants in the correct performance of CPR [3]. Instead of training and hoping for retention, perhaps teaching the participants to use and follow the steps in a checklist might offer some solution to the problem of retention. In this study we assessed the effects of two checklists which were used to guide the behaviors of undergraduates as they performed CPR.

2. Methods

2.1. Organization and equipment The subjects in this study were 169 undergraduates at a Midwest University who were enrolled in an elective class to be certified in basic life support skills. The basic strategy was to assess all students at the time of CPR certification testing, randomly assign them to a control and two experimental groups, and then re-test for retention 2 months later. At the time of re-testing, one experimental group used a wallet size short checklist (SC condition) published by the ARC that included diagrams as well as text identifying check, call and care procedures [7] (e.g. if no pulse or breathing — give CPR: repeat sets of 15 compressions and two breaths). The other experimental group used a longer and more detailed checklist (no diagrams) which outlines the specific procedure for CPR described in ARC ‘First Aid: Responding To Emergencies’ course manual [8] (the long checklist, or LC condition). The control group used no checklist.

2.2. CPR training and testing Students were tested using two Laerdal Skillmeter Resusci Anne recording manikins. Initial testing occurred at the time of the CPR course assessment. Retention testing occurred 2 months following the initial assessment. Students performed the retention test with little or no forewarning. Retention testing typically occurred as students exited or entered their regularly scheduled classes. At this time they were asked to accompany a investigator to a room where they found the manikin. Retention testing took place during a two-week period. No effort was made to prevent news of the testing from becoming public, though no evidence of this was observed.

2.3. Definitions Two groups of variables were created: procedural and compression – ventilation variables. Procedural variables represented critical elements of the CPR procedure and included: calling 911, performing the wrong

procedure (a procedure other than CPR was performed such as abdominal thrusts), head tilt, compression rate, and first pulse check. These critical elements represented the key steps or errors in performing CPR for the investigators. In addition, an overall-performance variable was created, summarizing performance on the procedural variables. Specifically, a subject’s performance was considered successful if the subject succeeded on all of the procedural variables. Each procedural variable was treated as a yes/no binary variable. The compression–ventilation variables were obtained from the recording manikin and measured the accuracy of the ventilations and compressions. The recording manikin provided a fine-grained analysis of ventilations and compressions, categorizing each as too little, just right, or too much. Because the depth of compressions and ventilations had to be within a small window for the manikin to register them as ‘just right’, we created a larger category of correct performance, counting those compressions and ventilations that were either too much or just right as correct. This yielded two measures for each subject (proportion correct for ventilations and proportion correct for compressions). Subsequent analyses based on the stringent (i.e. just right) and the more inclusive (i.e. just right and too much) definitions of correct performance led to identical conclusions. Only the analysis of the latter set of variables are reported below. The compression–ventilation ratio (C–V ratio) was assessed as a yes/no binary variable. The distinction between the first and second set of variables was made for two reasons. First, most CPR courses assess without the aid of recording manikins using checklists instead to determine competence, and as such the procedural variable represents a measure which is typically used in the majority of settings where CPR training occurs. Second, data obtained from the recording manikin provided quantitative measures of the depth of the compression and ventilations and allowed us to assess with some sophistication these aspects of the CPR performances which would not normally be possible on a non-recording manikin.

2.4. Statistical methods The effects of group on the yes/no binary variables (i.e. the procedural variables and C–V ratio) were assessed with x 2-square tests of independence (or Fisher’s exact test where expected frequencies were low). The proportions of ventilations and compressions categorized as correct were analyzed with the Kruskal– Wallis test, using group as the between-subjects factor. This non-parametric test was used because the dependent measures displayed significant non-normality, as assessed by the Lilliefors test.


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Table 1 Initial testing: proportions of subjects sucessfully completing different aspects of CPR

Table 3 Retention testing: proportions of subjects sucessfully completing different aspects of CPR as a function of group

Variable

Successful completion

Variable

Successful completion

Comparison

Group

na

Group

nb

P-valuea

%

Overall performance on procedural variables NC 13 SC 11 LC 9 Procedural call 911 NC 42 SC 40 LC 37 Correct procedure NC 54 SC 54 LC 55 Head tilt NC 33 SC 38 LC 30 Compression rate NC 26 SC 28 LC 28 First pulse check NC 56 SC 55 LC 52 C – V ratio NC 44 SC 47 LC 48

22 20 16 72 71 67 93 96 100 57 68 54 45 50 51 97 98 94 76 84 87

NC, no checklist; SC, short checklist; LC, long checklist. a Total n for each group: NC=58; SC= 56; LC= 55.

3. Results Data from the initial testing was used to verify that there were no group differences prior to instituting the experimental manipulation. Analyses of the binary variables and the proportions revealed no significant differences between groups at the time of initial testing (see Tables 1 and 2). The results of the retention testing for the binary Table 2 Initial testing: proportions of correct ventilations and compressions as a function of group Group NC

Ventilations Compressions

SC

LC

Mean

S.D.

Mean

S.D.

Mean

S.D.

0.52 0.46

0.43 0.37

0.53 0.46

0.41 0.34

0.52 0.45

0.43 0.38

NC, no checklist; SC, short checklist; LC, long checklist.

%

All groups, B0.01

Overall performance on procedural variables NC 8 14 SC 7 13 LC 18 33

NC vs. SC, ns NC vs. LC, B0.02 SC vs. LC, B0.01

Procedural call 911 NC 29 SC 29 LC 49

50 52 89

All groups, B0.001 NC vs. SC, ns NC vs. LC, B0.001 SC vs. LC, B0.001

Correct procedure NC 51 SC 48 LC 54

88 86 98

All groups, ns NC vs. SC, ns NC vs. LC, ns SC vs. LC, B0.03

Head tilt NC SC LC

28 41 42

48 73 76

All groups, B0.003 NC vs. SC, B0.007 NC vs. LC, B0.003 SC vs. LC, ns

Compression rate NC SC LC

25 19 30

43 34 54


First pulse check NC SC LC

48 44 51

83 78 93


C – V ratio NC SC LC

36 39 46

62 70 84

All groups, B0.04 NC vs. SC, ns NC vs. LC, B0.01 SC vs. LC, ns

NC, no checklist; SC, short checklist; LC, long checklist. a P-value denoted if P-value B0.05; otherwise ns, non-significant at the 0.05 level. b Total n for each group: NC= 58; SC= 56; LC= 55.

variables are presented in Table 3. For each variable, an analysis was conducted to determine if the proportions of successful subjects differed across all groups. Pairwise comparisons were conducted to determine if pairs of groups differed. Table 3 lists P-values for comparisons which yielded significant differences of PB 0.05. The long checklist led to generally superior performance on the summary variable. Here, the effect of group was significant, indicating that the long checklist led to superior performance compared with either no checklist or the short checklist. In addition, the long checklist was superior to the short checklist for the following specific procedural variables: call 911, performing the wrong procedure, compression rate, and the first pulse check. The long checklist was superior to no checklist for call 911 and head tilt. It should be


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Table 4 Retention testing: proportions of correct ventilations and compressions as a function of groupa Group NC

Ventilations Compressions

SC

LC

Mean

S.D.

Mean

S.D.

Mean

S.D.

0.50 (0.44) 0.34 (0.33)

0.38 (0.39) 0.34 (0.34)

0.47 (0.44) 0.34 (0.32)

0.41 (0.41) 0.31 (0.31)

0.56 (0.51) 0.43 (0.39)

0.40 (0.41) 0.40 (0.37)

NC, no checklist; SC, short checklist; LC, long checklist. Means and S.D.s excluding (and in parentheses, including) subjects with zero valid ventilations or compressions.

a

noted that with regard to the procedural variables, the short checklist and the no checklist conditions led to comparable levels of performance, except for the head tilt variable, where the short checklist led to a significantly better performance. Finally, the experimental manipulation affected the C – V ratio as well. Specifically, the long checklist led to significantly better performance than no checklist. Several students failed to register any compressions or ventilations on the manikin recording equipment. The number of subjects registering zero compressions was 11 (6.5% of the total number): three from each of the no checklist and short checklist groups and five from the long checklist group. The number of subjects registering zero ventilations was 14 (8% of the total number): seven from the no checklist group, three from the short checklist group and four from the long checklist group. These frequencies did not significantly differ across groups for either ventilations or compressions. All analyses were carried out in two ways, once excluding subjects with zero compressions/ventilations and again including these subjects, assigning a value of zero for the correct proportion. For all analyses, the conclusions were identical. The results of the ventilation and compression data are presented in Table 4. The analyses indicate that neither the proportions of correct ventilations nor compressions significantly varied across experimental groups.

4. Discussion A number of important findings arise from this study. First, the results of the summary variable indicate that the group using the detailed checklist was more effective in performing correct CPR than either the short version group or the group performing without a checklist. In addition, the individual variables of the procedure were either at least as effective with the detailed checklist or significantly more effective than either of the other groups. For example, 89% of the students in the long checklist group remembered to call 911 compared with approximately 50% of those in the

no checklist or the short version groups. There were also fewer wrong procedures performed by members of the long checklist group (98% correct) than either of the other groups (88 and 86% correct). Second, although there were no significant differences among groups on the proportions of correct compressions or ventilations, the groups did differ on the C–V ratio variable. However, the successful completion by members of the long checklist group was only 84%. It appears that while procedural steps can be prompted, the depth of compression and ventilations may be more difficult to train for and retain. This finding is compounded by the differences between training and assessment conditions. During the CPR course performances were conducted on non-computerized manikins. These manikins were older and discriminations between the depth of compressions and ventilations were approximate. In contrast, students received two trials using the recording manikins—one at the time of the initial testing and the other at the time of retention assessment. It may be that not having received the feedback from the computerized manikin during training, regarding the depth of compressions and ventilations, that the results are not as representative of how well trained individuals would perform. On the other hand the majority of CPR training in the US does not occur using recording manikins in which case these data have high ecological validity. Third, using the detailed version of the checklist did not appear difficult for the students in this study. We gave the short and long checklists to the students at the time retention testing, this was the first time that they had seen them. What would have been the effects of group performances if they had been taught to use the checklist? Perhaps the results of the retention test may have been more significant on the overall summary variable. Arguing in favor of the use of a checklist to prompt CPR performance assumes that a checklist is present at the time of need. We think it is unlikely that the lay public would carry around such a checklist of their own volition. However, many people do carry car insurance and health insurance cards in their wallets and purses.


Typically these cards are blank on one side. Though our findings represent a single study, if further studies replicated our effects then a case might be made to insurance companies to print CPR procedures on the back of insurance cards. Furthermore, basic life support course instructors might train the lay public to take the cards from the wallet/purse and use the card to prompt CPR performance during the course. Though the detailed checklist improved performance on the overall performance variable, an important outcome of this study is the difference between the groups on the variable calling 911. There is abundant evidence in the form of anecdotal reports from citizens who have saved the life of another, from television reports in the popular press (e.g. Rescue 911) and from the on-scene police reports, that armed with nothing more than a telephone, individuals regardless of their experience can be prompted to perform basic life support skills and can do so well enough to save a life. The one step that the lay public needs to remember to do in an emergency is to call 911 immediately. For lay persons at least, perhaps calling 911 is the critical skill to maintain, not merely to ensure that an ambulance is dispatched, but also to ensure that the rescuer is in contact with trained personnel who can prompt and direct the behavior of the rescuer. In this study using the checklist considerably improved the likelihood of 911 being called immediately.

5. Conclusions The results of this study support our original hypothesis that remembering the steps of CPR is too complex for some. Using the detailed checklist was an effective

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alternative strategy to prompt the performance of CPR skills following course conclusion. This is one of the few studies that has reported an effective alternative to training and hoping that CPR will be performed correctly.

Acknowledgements This research was supported by grants from the Asmund S. Laerdal Foundation and the Laerdal Medical Corporation.

References [1] National conference on cardiopulmonary resuscitation and emergency cardiac care. Guidelines for cardiopulmonary resuscitation and emergency cardiac care, 1992. [2] Kaye W, Rallis SF, Mancini ME, Linhares KC, Angell ML, Donovan DS, Zajano NC, and Finger JA. The problem of poor retention of cardio-pulmonary resuscitation skills may lie with the instructor, not the learner or the curriculum. Resuscitation 1991; 21: 61 – 87. [3] Ward P, and Ward MC. The effects of classwide peer tutoring on correct cardiopulmonary resuscitation performance by physical education majors. J Behav Educ 1996; 6: 331 – 342. (In Press) [4] Kaye W, Montgonery W, Hon D et al., Interactive computervideodisc CPR training and testing. Circulation 1983; 68 (suppl. III): 111 – 114. [5] Plank CH, and Steinke KR. Effect of two teaching methods on CPR retention. J Nurs Staff Dev 1989; 5: 145 – 147. [6] Friesen L, and Stotts NA. Retention of basic cardiac life support content: The effect of two teaching methods. J Nurs Educ 1984; 23: 184 – 191. [7] American Red Cross. Adult Lifesaving Steps: Check Call Care. Mosby, St. Louis, 1993. [8] American Red Cross. First Aid: Responding to Emergencies. Mosby, St. Louis, 1993.