|Volume 21, Number 1||Spring, 1994|
The College of Veterinary Medicine at Michigan State University recently approved a new curriculum. The changes limited preclinical experiences to those general didactic presentations and psychomotor-skill laboratories judged appropriate for all veterinary students, regardless of their specific interests. The clinical portion of the curriculum was lengthened to allow expanded elective opportunities and more in-depth study within specific discipline and/or species specialties. In the original curriculum, the theriogenology course included a progression of three laboratories that emphasized transrectal palpation of the bovine reproductive tract. Within the new curriculum, only one laboratory session is offered.
During the production medicine rotation, students participate in service visits to commercial dairy farms. Assessment of individual animal reproductive status is a major part of the service. If students spend too long conducting basic palpations, clients lose valuable time. Our concern about a reduction in the number of palpation laboratories was that students' skills to assess reproductive status in client-monitored settings would be reduced.
The purpose of this research was to develop a bovine palpation skills index and to measure students' palpation skills. The index had to show students an explicit view of the instructor's expectations, what skills were attainable, and their current skill level (1). We hoped to predict the impact of a reduction in the number of laboratories on student skill levels.
Materials and Methods
We studied student skill attainment with the class of 1993 ('93) during both preclinical laboratories and clinical opportunities and with the class of 1994 ('94) only during preclinical laboratories. A palpation skills score (SCORE) was determined for all students prior to the first palpation laboratory (PRE-LAB), after completion of the first laboratory (FIRST LAB), and after completion of the last laboratory (LAST LAB). A SCORE was determined for '93 students after completion of their first service-related experience within the production medicine rotation (PM 1) and at the end of the production medicine rotation (PM 2). After the '93 preclinical studies were completed, the number of laboratories was unexpectedly changed; the '94 students completed a series of two, instead of three, laboratories. This change provided the opportunity to measure skill attainment after one, two and three laboratories.
Table 1. The Bovine Palpation Skills Index with a description of each specific skill and an indication of the new competency required.
Score Skill Description New Competency
1 No predictable ability. 2 Describes position of the Recognizes the search reproductive tract from pelvic area for the reproductive to abdominal. organs and understands when retraction is required. 3 Describes the cervix. Locates and grasps the cervix to approximate its diameter(s). 4 Describes the cervix and Recognizes the difference locates the uterine horns. between cervix and uterus; determines if the horns require uncoiling. 5 Describes the cervix and Surrounds and estimates the uncoiled uterine horns. diameter of each uterine horn. 6 Describes the reproductive Locates and grasps each ovary using tract including the ovaries. the uterine horns as a guide to the search area; determines the size and shape of each ovary. 7 Describes the reproductive Predicts when the ovaries contain luteal tract including major ovarian structures and large (>15 mm) follicles. structures. 8 Completely describes the Recognizes smaller follicles of reproductive tract and ovaries. about 10 mm diameter. 9 Independently performs Routinely uses retraction reproductive tract palpations. and uncoiling techniques without instructor assistance. 10 Demonstrates knowledge of Compares width and depth of the ovarian bursa palpation. ovarian bursas to fingers.
With the following exceptions, the first author (instructor) taught all bovine reproductive palpation laboratories and performed palpations with each student that rotated through the production medicine service. The '93 preclinical population of 75 students was reduced during the clinical portion of the study to 69 students because of individual instances when the instructor was unable to schedule a second, comparative palpation opportunity. The '94 preclinical population was reduced from 111 to 95 students because the instructor did not attend the first laboratory session for one student group. Since these were unplanned events, they were considered unbiased reductions in the study populations.
Bovine Palpation Skills Index: The bovine palpation skills index (Table 1) was based upon the nonpregnant, reproductive tract examination method taught by the instructor. Students were encouraged to learn a complete palpation examination (2, 3), rather than becoming enamored with ovarian palpation, by ordering their efforts and by initially teaching ovarian location as a function of cervical and uterine horn position. The order of the index skills reflected the instructor's observations describing how most students gain competency.
Students first learn to determine when portions of the reproductive tract are abdominal or entirely pelvic in location (skill 2). Next, the cervix is located and described (skill 3). Complete examination of each uterine horn (skill 5) first requires general location of the uterus, discovery of the bifurcation of the horns, and recognition of their more ventral, coiled portions (skill 4). Retraction of the uterus, from positions cranioventral to the pelvic brim, and uncoiling of the uterine horns, from "beneath" the broad ligament and cervix, are gradually mastered (skill 9). When required, students attempt described re-positioning methods, but are asked to seek instructor assistance to prevent frustration. Location of each ovary and description of ovarian size and shape (skill 6) begins the process of ovarian palpation (3). Recognition of major and then minor ovarian structures completes the typical reproductive examination (skills 7 and 8). Location of the ovarian bursas (skill 10) is the final part of a complete examination.
Assignment of a Palpation Skills Score: After a detailed explanation of the palpation skills index, each student completed a PRE-LAB self-assessment by selecting the SCORE that best predicted his/her experience-based expectation of what would be accomplished during palpation of the first laboratory cow. Those without prior experience were instructed to select skill 1.
Assigned SCORES represented a consistent competency and not the erratic accomplishment of a specific skill. FIRST LAB and LAST LAB SCORES were assigned by direct comparisons between the results of student ('93 and '94) and instructor palpations. Students were not able to merely indicate having found or identified a predescribed structure, instead, they described or demonstrated the location, size, and shape of the palpable structures. PM 1 and PM 2 SCORES (only '93 students) were assigned by direct comparison to the instructor's palpation and occasionally included information from other clinicians. Data collected at each scoring opportunity were recorded on separate forms to prevent the instructor from knowing a student's last SCORE. A computer spreadsheet program was used to collate and analyze the data (4).
Students were requested to indicate extra-curricular palpation experience gained prior to the FIRST LAB or between the LAST LAB and PM 1. Both the type of experience and number of cows palpated were recorded. PRE-LAB experience was used to classify students into novice and prior experience subpopulations. The latter classification was assigned if 5 or more cows had been palpated under veterinary supervision or if formal artificial insemination training had been completed. This somewhat subjective assignment was thought to approximate minimal effort in one theriogenology course laboratory.
Table 2. Summary statistics for Bovine Palpation Skills Score at indicated opportunities.
Scoring* Student** Palpation Skills Score Opportunity Population No. Mean S.D. Variance
PRE-LAB '93 75 1.95 1.65 2.73 '94 95 1.62 1.03 1.07 Experienced 51 3.41 1.40 1.97 Novice 119 1.06 0.30 0.09 All 170 1.76 1.35 1.81
FIRST LAB '93 75 3.60 1.19 1.40 '94 95 3.40 0.99 0.99 Experienced 51 3.98 1.10 1.21 Novice 119 3.28 1.01 1.02 All 170 3.49 1.08 1.17
LAST LAB '93 75 5.19 1.39 1.94 '94 95 4.71 1.24 1.55 Experienced 51 5.65 1.21 1.47 Novice 119 4.61 1.27 1.58 All 170 4.92 1.33 1.76
PM 1 '93 69 3.96 1.34 1.81 Experienced 22 4.73 1.39 1.92 Novice 47 3.60 1.17 1.38
PM 2 '93 69 6.74 1.33 1.78 Experienced 22 7.36 1.05 1.10 Novice 47 6.45 1.36 1.86
* PRE-LAB, FIRST LAB, LAST LAB, PM 1, AND PM 2 indicate scoring done before the first laboratory, after the first laboratory, after the last laboratory, after the first production medical experience, and at the completion of the production medicine rotation, respectively.
** '93, '94, Experienced, Novice, and All indicate students from the class of 1993, class of 1994, with prelaboratory experience, without prelaboratory experience, and all students, respectively.
The experimental design was a repeated measures split-plot (5). For the first statistical model (n=170), class and experience (prior experience, novice) were independent variables and the repeated dependent variable was the SCORE measured at PRE-LAB, FIRST LAB and LAST LAB. A second split plot model was limited to the 69 students ('93) who had both PM 1 and PM 2 SCORES. Statistical analysis was performed with SAS (6).
A total of 170 students were evaluated during their preclinical palpation opportunities. The number of students within the '93, '94, experienced and novice subpopulations were 75, 95, 51 and 119, respectively. Table 2 presents the summary SCORE data for the student populations at each scoring opportunity.
Both split-plot models showed that previous experience and the time of evaluation (repeated variable) were highly significant (P<0.0001). Although of only marginal overall significance (P=0.044), class was most associated with SCORE at the time of the last laboratory (P=0.03), reflecting the '93 versus '94 difference in number of laboratories. Using MANOVA tests, the hypothesis of no time effect and the hypothesis of no time*experience interaction were rejected (P<0.0001) for both models. The hypothesis of no time*class effect could not be rejected (P=0.29) in the first model.
Mean SCORE for all students started at 1.76 (PRE-LAB) and progressed to 3.49 (FIRST LAB) and 4.92 (LAST LAB). Frequency polygons that demonstrate the distribution of the quantitative SCORES are shown in Figure 1. Mean PRE-LAB SCORES for '93, '94, prior experience, and novice students were 1.95, 1.62, 3.41 and 1.06, respectively. The '93 and '94 SCORES were similar and experienced students predicted greater ability than the novice students. Mean FIRST LAB SCORES for '93, '94, prior experience, and novice students were 3.60, 3.40, 3.98 and 3.28, respectively. The '93 and '94 SCORES did not differ and the experienced students scored higher than the novice students. Similarly, the mean LAST LAB SCORES were 5.19, 4.71, 5.65 and 4.61, respectively. Experienced students continued to score higher than novice students.
The '93 students (3 labs) scored higher than the '94 students (2 labs); frequency polygons of SCORE demonstrated a positive effect from the extra laboratory (Figure 2). Mean SCORES for '93 students decreased form 5.19 after the LAST LAB to 3.96 after PM 1 and then increased dramatically to 6.74 after PM 2. Frequency polygons of SCORE are shown in Figure 3.
Figure 1. The frequency distribution (frequency polygons) of palpation skills scores at each preclinical evaluation opportunity.
Figure 2. Frequency distribution of palpation skills score after 1, 2, and 3 laboratories.
Figure 3. Frequency distribution of palpation skills scores comparing the last laboratory to the clinical evaluation opportunities, Class of '93. (Last Lab, n=75; ProdMed 1, n=69; ProdMed 2, n=69).
Since many colleges of veterinary medicine are undergoing or have recently implemented curricular changes, the results of this study should be of general interest to both veterinary educators and the potential employers of students. If curricular changes reduce specific preclinical skills, client participation in clinical training programs may be discouraged.
The bovine palpation skills SCORE explicitly provided students with a benchmark for comparison of their current ability to possible skill attainment. Prior to completing this study, the range of performance was not known and the typical attainment of bovine palpation skills could not be described. During this study, knowledge of their current SCORE seemed to motivate students to strive for added competency. Use of the index can provide students with a comparison of their performance versus performance of others. If dramatically different instruction methods are used, extrapolation of results may not be justified. However, our index could provide a template for similar efforts by others.
Students seemed to accurately assess their prelab skills (Figure 1). Novice students predicted almost no skills and students with prior experience predicted skills that centered on the ability to describe the cervix. Since almost all student experience involved only extracurricular artificial insemination training, the self-assessment appeared realistic.
The distribution of FIRST LAB SCORE for all students (Figure 2) indicated that most students learned to palpate the cervix and describe the location of the uterine horns. The distribution of LAST LAB SCORE (Figure 1) covered a wider SCORE range with many more students demonstrating skills that included palpation of the ovary. Students that completed 3 instead of only 2 laboratories (Figure 2), demonstrated an improved distribution of SCORES. In addition, prior experience was always associated with an increased SCORE (Table 2). To assess the effect of reducing the number of laboratories, the SCORE decrease between the LAST LAB and PM 1 (Figure 3) was an important observation.
In our practice environment, we believe that if students attain only those abilities indicated by the FIRST LAB SCORES, their predicted clinical proficiency would be inadequate for palpating client-owned animals. Palpation of client-owned animals might have to be limited to students that had first gained additional experience.
A bovine reproductive palpation index was created and used to assign palpation skill scores. The results from 2 split-plot models were presented. In the first model, class and prelaboratory experience were significant independent variables and the repeated dependent variable was the score at the various curricular opportunities. Students with extra-curricular, prelaboratory experience consistently scored higher than novice students. The mean score increased for all student subpopulations, with the number of laboratory experiences. The second model dealt only with '93 students during both preclinical and clinical curriculum scoring opportunities. A decrease in the mean score between the last laboratory and the first clinical experience was observed before a dramatic score rise at the end of the clinical experiences.
If students attained only those preclinical abilities represented by the mean of the first laboratory scores, their predicted clinical proficiency would be less than we believe are essential for palpating client-owned animals.
References and Endnotes
1. West CK, Farmer JA, Wolff PM: Instructional Design: Implications from Cognitive Science. Englewood Cliffs, NJ: Prentice Hall, 1991, pp 50-77.
2. Noakes DE: The normal genital organs. In Laing JA, Brinley-Morgan WJ, Wagner WC: Fertility and Infertility in Veterinary Practice, ed 4. London: Bailliere Tindall, 1988, pp 23-28.
3. Arthur GH, Noakes DE, Pearson H: Veterinary Reproduction and Obstetrics, ed 6. London: Bailliere Tindall, 1989, pp 70-73.
4. PANACEA: User's Guide. Reading, England: Pan Livestock Services Limited, 1986, pp 31-33.
5. Gill JL: Design and Analysis of Experiments in Animal and Medical Sciences, vol 2. Ames, IA: The Iowa State University Press, 1978, p 210.
6. Statistical Analysis System for Personal Computers (SAS-PC). Cary, NC: SAS, 1991.
7. This work was supported by the Office of Academic and Student Affairs, College of Veterinary Medicine, Michigan State University.