MEDICAL EDUCATION

Effects of Four Supplemental Instruction Programs onStudents’ Learning of Gross Anatomy

JOSEPH P. FORESTER, PAMELA P. THOMAS, AND DAVID L. MCWHORTER*

University of Health Sciences College of Osteopathic Medicine, Kansas City, Missouri

Many researchers have reported that supplemental instruction programs improve medicalstudents’ performance in various basic sciences. This study was conducted to evaluate thesummative effects of four supplemental instruction programs (i.e., second-year medicalstudent teaching assistant program; directed study program; weekly instructor laboratoryreviews; and a web-based anatomy program) on medical students’ gross anatomy laboratorypractical performance. First-year medical students from the graduating class of 2006 (n �223) received the four supplemental instruction programs (Experimental Group). The ControlGroup consisted of first-year medical students from the graduating class of 2005 (n � 254)who did not receive the four supplemental learning methods. Mann-Whitney rank sum testswere used to compare the two groups’ median percentages for the back-upper limb (B-UL)and the lower limb (LL) parts of a gross anatomy laboratory practical. The ExperimentalGroup’s median percentages for both the B-UL (77.78%) and LL (83.33%) were significantlygreater than that of the Control Group (B-UL � 69.00%; LL � 81.00%; P � 0.05). Resultsfrom a post-hoc student survey showed that more students both rated and ranked the weeklyinstructor laboratory reviews as extremely useful and most beneficial, respectively. A greaternumber of students rated and ranked the web-based anatomy program as not useful and leastbeneficial, respectively. The results from this study suggest that the four supplementalinstruction programs improved students’ learning of gross anatomy as measured by labora-tory practical performance. In addition, students most valued the additional time in the grossanatomy laboratory with the instructors. Clin. Anat. 17:322–327, 2004.© 2004 Wiley-Liss, Inc.

Key words: education; medical curriculum; alternative teaching methods

INTRODUCTION

The curricular transition of some medical schoolsfrom using a traditional discipline-based curriculum toan integrated basic and clinical science program hascreated a challenge for teaching gross anatomy(Mandin et al., 1995; Drake, 1998; Blue et al., 2000;Woloschuk, 2000; Vidic and Weitlauf, 2002). The in-tegration of basic and clinical science in medicalschool curricula has resulted in less time for grossanatomy lectures and laboratories (Cottam, 1999; Azizet al., 2002). Consequently, many anatomists are usingalternative/supplemental methods for teaching grossanatomy, particularly in the laboratory.

To enhance students’ learning of gross anatomy,Op den Akker et al. (2002) implemented the use ofbody paint in the gross and living anatomy courses atUtrecht Medical Center. The entire class of first-yearmedical students (n � 240) painted abdominal and

thoracic organs on each others skin surface during two3-hr laboratory sessions. Results from students’ eval-uations (97.5% response rate) indicated increased en-thusiasm towards learning anatomy, and that the sup-plemental method of body painting provided insightinto the spatial relations of internal organs.

The effects of supplemental instruction in bio-chemistry, gross anatomy, microbiology, and physiol-ogy on mean test scores were studied by Sawyer et al.(1996). In this study, second-year medical studentsdirected an optional, supplemental instruction pro-

*Correspondence to: David L. McWhorter, PhD, Department ofAnatomy, UHS-COM, 1750 Independence Avenue, Kansas City,MO 64106. E-mail: dmcwhorter@uhs.edu

Received 11 February 2003; Revised 15 May 2003

Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ca.10219

Clinical Anatomy 17:322–327 (2004)

© 2004 Wiley-Liss, Inc.

gram to all 150 first-year medical students at the Uni-versity of Southern California School of Medicine.The results of this study demonstrated significantincreases in mean test scores for the students (n �127) who received the supplemental instruction. Ad-ditionally, failure rates for “at-risk” students (i.e.,composite Medical College Admission Test score of�26 and a science grade-point average below 3.0) inthe supplemental instruction group decreased by 46%when compared to previous classes.

Hallgren et al. (2002) evaluated gross anatomy lab-oratory examination performance after supplementinganatomy instruction with a web-based anatomy pro-gram. Sixty-three of the 124 first-year medical stu-dents at Michigan State University College of Osteo-pathic Medicine used the web-based anatomyprogram. The results of this study showed that the 63students who used the web-based program performedsignificantly better on both mid-term and final grossanatomy laboratory exams than the students who didnot use the web-based program.

Peer teaching is yet another supplemental methodused by some anatomists to instruct their students.Yeager and Young (1992) implemented a system ofpeer teaching due to decreased course hours and fac-ulty time, and to increased class size. Eight studentswere assigned to each cadaver and teams of two stu-dents performed every fourth dissection. Studentevaluations from this study indicated that peer teach-ing was an effective learning tool. Additionally, theauthors reported no change in national board exami-nation performance following the implementation ofthe peer-teaching program.

In another peer-teaching study, Nnodim (1997)compared students in a “traditional” dissecting pro-gram with students in an experimental peer-teachingprogram. A total of 160 second-year medical studentswere divided into two equal groups. One group, serv-ing as the Control dissected in every anatomy labora-tory. The other group (Experimental) was further di-vided into two subgroups that participated in a peer-teaching program. In the peer-teaching program, eachhalf of the Experimental Group participated in 50% ofthe dissections and teaching. Results from this studyshowed that the students in the peer teaching pro-gram performed significantly better than their full-time dissecting counterparts on both a two-choicetheory paper and a 50-station practical exam.

In the fall of 2002, we implemented four newsupplemental instruction programs in the gross anat-omy course at the University of Health Sciences Col-lege of Osteopathic Medicine (UHS-COM). The foursupplemental instruction programs consisted of thefollowing: 1) second-year medical student teaching

assistant program, 2) directed study program, 3)weekly instructor laboratory reviews, and 4) web-based anatomy program. These pilot programs were inresponse to an internal S.W.O.T. (i.e., strengths,weaknesses, opportunities, and threats) analysis per-formed by the Continuous Quality Improvement(CQI) teams at UHS-COM. The CQI teams werecomprised of first- and second-year students, UHS-COM faculty, and Curriculum Department staff.Thus, the purpose of this study was to assess thesummative effect of four supplemental instructionprograms on students’ gross anatomy laboratory prac-tical performance.

MATERIALS AND METHODS

During the 2001–2002 academic year, first-year stu-dents in the graduating class of 2005 (n � 254) dis-sected in every other 3-hr gross anatomy laboratory(Control Group). After completing the back, upperlimb, and lower limb dissections, students were givena 50-question identification-based (e.g., Identify thetagged structure?) or tag-related (e.g., Which muscle issupplied by the tagged structure?) laboratory practical.The number of back, upper limb, and lower limbquestions related to the number of corresponding lab-oratories. Two anatomy department instructors gradedall laboratory exams using a standardized key.

The same teaching and testing protocol was fol-lowed during the 2002–2003 academic year for thefirst-year students in the graduating class of 2006 (n �223). This group of students (Experimental Group),however, received the following supplemental in-struction programs (SIPs; Table 1): 1) second-yearmedical student teaching assistant program (TA), 2)directed study program (DS), 3) weekly instructorlaboratory reviews (IR), and 4) a web-based anatomyprogram (WP).

A total of 24 second-year medical students from ofthe graduating class of 2005 were selected to assistUHS-COM anatomy faculty in the laboratory teachingof gross anatomy. Criteria that anatomy faculty usedfor selecting second-year teaching assistants were astrong interest in teaching anatomy, an aptitude ingross anatomy (i.e., �80% average in gross anatomy),and an upper 30% class rank. Teaching assistants metwith anatomy faculty prior to each laboratory sessionto discuss the objectives for each dissection and toreview structures on a prosected specimen. Moreover,teaching assistants were required to attend at least onegross anatomy laboratory per week. Second-year stu-dents earned college credit for their participation inthe anatomy teaching assistant program.

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Because of the alternating dissection program atUHS-COM, students perform 50% of the gross anat-omy dissections. Students in the Control Group reliedmainly on independent study to learn the anatomythat they did not dissect. For the ExperimentalGroup, a directed study program was implemented.The required directed study program consisted of aweekly 1-hr laboratory session in which students inthe Experimental group reviewed the dissection per-

formed by their peers with the anatomy instructorsand teaching assistants.

Weekly 2-hr instructor laboratory reviews wereanother supplemental instruction program offeredto the Experimental Group. This optional programgave interested students an instructor-directed re-view of dissected material and an additional oppor-tunity to ask the instructor questions in the labora-tory setting.

TABLE 1. Timetable for Supplemental Instruction Programs Implementation*a

Week Day

1

Tu Orientation & Superficial Back Osteopathic Principles & Practices (OPP) Laboratory& Pathology Laboratory

Th Introduction to Clinical Medicine (ICM) Laboratory& Independent Study

Directed Study: Orientation & Superficial BackBack & Shoulder Regions

F Instructor review

2

Tu Directed Study: Back & Shoulder RegionsPathology Laboratory & Physiology LaboratoryIntermediate and Deep Back Muscles,

Suboccipital Triangle, & Spinal CordTh

Independent studyDirected Study: Intermediate and Deep Back

Muscles, Suboccipital Triangle, & Spinal CordBreast, Pectoral Region, Axilla, & Brachial

PlexusF Instructor review

3

Tu Directed Study: Breast, Pectoral Region, Axilla, &Brachial Plexus OPP Laboratory & Pathology Laboratory

Brachial Plexus, Arm, & Cubital FossaTh

ICM Laboratory & Independent StudyDirected Study: Brachial Plexus, Arm, & Cubital

FossaAnterior Forearm & Hand

F Instructor review

4

Tu Directed Study: Anterior Forearm & Hand OPP Laboratory, Pathology Laboratory, &Microbiology LaboratoryHand, Posterior Forearm, & Upper Limb Joints

ThICM Laboratory & Independent Study

Directed Study: Hand, Posterior Forearm, & UpperLimb Joints

Superficial Structures, Anterior & Medial ThighMuscles

F Instructor review

5

Tu Directed Study: Superficial Structures, Anterior &Medial Thigh Muscles OPP Laboratory & Pathology Laboratory

Gluteal Region & Posterior ThighTh

ICM Laboratory & Independent StudyDirected Study: Gluteal Region & Posterior ThighLeg & Dorsum of the Foot

F Instructor review

6

M Directed Study: Leg & Dorsum of the FootOPP LaboratorySole of the Foot & Lower Limb Joints

OPP Laboratory Sole of the Foot & Lower Limb JointsTu Instructor reviewTh Gross anatomy laboratory practical

*Bold titles indicate laboratory dissections for one-half (n � 112) of first-year class (N � 223), while the other one-half (n � 111) offirst-year class participated in simultaneously scheduled non-anatomy activities.aLibrary staff provided small group instructions on using the web-based anatomy program to all students in the Experimental groupbefore commencing gross anatomy.

324 Forester et al.

The fourth supplemental program offered to theExperimental Group was a web-based anatomy in-struction program titled “Human Anatomy” (Rarev etal., 2001). The Human Anatomy Online program of-fered to the Experimental group consisted of threemain instructional parts: 1) “Dissector,” 2) “Quiz,”and 3) “Clinical Correlations.” After entering a loginname and password, students had unlimited access tothe web-based program from both on- and off-campus.

The purpose of this study was to evaluate thecollective effect of these four supplemental instruc-tion programs on anatomy laboratory practical perfor-mance. Therefore, anatomy laboratory practical per-formance of students who received these programs(Experimental Group) was compared to students whowere not exposed to the four supplemental instructionprograms (Control Group).

Because of the functional and structural continuityof the back and the upper limb, laboratory practicalperformance for these two regions was combined. Asecond reason for combining back and upper limbperformance was that the same instructor taught bothregions. Hence, we denote back and upper limb labpractical questions/performance in this study as back-upper limb (B-UL) questions/performance. On thelaboratory practical, B-UL and lower limb (LL) ques-tions were randomly positioned for both the Controland Experimental groups. As a result, individual stu-dents’ performance for the B-UL and the LL had tobe determined first. After the number of correct B-ULquestions was determined for each student, these datawere entered into a Microsoft Excel™ file. The use ofMicrosoft Excel™ program formulas enabled us todetermine quickly, the number of correct LL ques-tions for each student. Because the total number ofB-UL and LL questions were unequal, we used an-other Microsoft Excel™ formula to convert the correctnumber of B-UL and LL questions for each studentinto percent correct (e.g., 24 correct back-upper limbquestions � 27 total back-upper limb questions �88.9%).

For statistical analysis, percent correct averages forthe B-UL and the LL were calculated for the Controland Experimental groups. Student’s t-tests were usedto compare the B-UL limb means and LL means ofthe two groups. An alpha level for significance was setat 0.05. Sigma Stat™ for Windows (version 2.03, SPSS,Inc.) was used for all statistical analyses.

RESULTS

Because the purpose of the study was to examinethe summative effects of four different supplementalinstruction programs on anatomy laboratory examina-

tion performance, a Student’s t-test was used to sta-tistically compare the back-upper limb (B-UL) meansof the Experimental and Control groups. The normal-ity assumption of the parametric test failed, however,during execution of a Student’s t-test. As a result, aMann-Whitney rank sum test was used and revealed asignificant difference in median values for the B-ULof the two groups (P � 0.05; Table 2). Descriptivestatistics showed that the B-UL mean � SD for theExperimental Group (72.65 � 17.16) was 4.55%greater than the Control Group (68.01 � 13.74; Fig. 1).

A Student’s t-test was also used to statistically eval-uate the collective effects of the four supplementalmethods on lower limb (LL) anatomy lab practicalperformance of the Experimental and Control groups.Again, the normality test failed and a Mann-Whitneyrank sum test was utilized. The LL median value forthe Experimental Group was significantly greater thanthat of the Control Group (P � 0.05; Table 2). TheLL mean � SD of the Experimental Group (78.33 �16.77) was 2.75% greater than that of the ControlGroup (75.57 � 14.46; Fig. 1).

DISCUSSION

Development and implementation of the four Sup-plemental Instruction Programs (SIPs) into our grossanatomy program were the result of the S.W.O.T.(strengths, weaknesses, opportunities, and weak-nesses) analysis. The S.W.O.T. analysis was con-ducted by the Continuous Quality Improvement(CQI) teams at the University of Health SciencesCollege of Osteopathic Medicine (UHS-COM). For-mation of the CQI teams coincided with the change ofour traditional curriculum to an integrated, clinicalpresentation-based curriculum in the fall of 2000.

Our new integrated, clinical presentation-basedcurricular model was patterned after the program usedat the University of Calgary (Mandin, et al., 1995).UHS-COM students receive the preclinical portion oftheir medical education via specific clinical presenta-tions (e.g., patients with murmurs, patients with ab-dominal pain, and patients with joint pain) within 14

TABLE 2. Mann-Whitney Rank Sum Test Results for theControl and Experimental Groups

Region Group (n) Median 25% 75%

Back-upper limb Control (254) 69.00 58.60 79.30Experimental (223) 77.78* 59.26 85.19

Lower limb Control (254) 81.00 66.70 85.70Experimental (223) 83.33* 67.71 91.67

*Significant difference (P � 0.05) between the two groups for theback-upper limb, and the two groups for the lower limb.

Supplemental Instruction and Lab Performance 325

system-based sections (e.g., Cardiovascular, Gastroin-testinal, and Musculoskeletal).

The CQI teams were formed to assess the effec-tiveness of our newly implemented curriculum. Foreach section, three students were randomly selectedby the UHS-COM Evaluation Specialist to serve asthe section’s CQI team. The chief responsibility ofeach CQI team was to communicate class feedback tothe faculty and administration regarding the quality oftheir section. After the first class of students com-pleted all 14 sections of the new integrated, clinicalpresentation-based curriculum (i.e., 2 years), theUHS-COM Evaluation Specialist convened all CQIteams and conducted a strengths, weaknesses, oppor-tunities, and threats (S.W.O.T.) analysis in 2002. Asthe acronym implies, the objectives of the analysiswere to discuss the new curriculum’s strengths, weak-nesses, opportunities for improvement, and threats forthe continued viability.

Results from the S.W.O.T. analysis indicated thatthe integration of the basic and clinical sciences was astrength of the new curriculum, and that it helpedthem in “learning how clinicians think.” Some areasthat they felt needed improvement (“weaknesses”)were, “low-yield afternoon labs…a high ratio of stu-dents to faculty in labs…an emphasis on the use ofcomputers without good equipment or plan.” Severalsuggestions for improving the curriculum (“opportu-nities”) were to “have more intensive times forlabs…increase the number of teaching assistants inlabs…provide better computers and computer re-sources.” Areas affecting the viability of the new cur-riculum (“threats”) included, “instructors that are notavailable” and “lack of unstructured study time.”Thus, the data stated previously was the impetus forimplementing the four SIPs into our gross anatomyprogram.

Simultaneously implementing four SIPs into ourgross anatomy program prevented us from determin-ing the individual effect of each program on students’laboratory practical performance. To understand bet-ter the effect of each SIP, however, we conducted apost-hoc student survey.

An anonymous and voluntary survey was adminis-tered to the graduating class of 2006 (Experimentalgroup; n � 223). A total of 170 surveys were com-pleted and returned (76.23% response rate). Studentswere first asked to rate each SIP, using the followingscale: “1” indicating not useful, “2” indicating some-what useful, “3” indicating useful, and “4” indicatingextremely useful. Because each rating could be usedmore than once, it was possible for each SIP to receivethe same rating from a student. Data from this portionof the survey were analyzed using a one-way analysisof variance (Fig. 2). A post-hoc Dunn’s test revealed asignificant difference between the weekly instructorlaboratory reviews (IR) and the web-based anatomyprogram (WP), indicating students’ preference of theIR to the WP. All other pairwise comparisons werestatistically equivalent.

The second purpose of the survey was to havestudents rank each SIP, using the following scale: “1”indicating the most beneficial, “2” indicating secondmost beneficial, “3” indicating third most beneficial,and “4” indicating least beneficial. Results from thispart of the survey showed that the weekly IRs wereranked as “most beneficial” to students, whereas theWP was perceived as the “least beneficial” (Table 3).Unsolicited student comments on the survey suggest

Fig. 1. Back-upper limb (B-UL) and lower limb (LL) grossanatomy laboratory practical performance for Control and Experimen-tal groups (values are means � SD). *Significant difference (P �0.05) between the two groups.

Fig. 2. Student survey rating results of the four supplementalinstruction programs (values � means � SD). The student surveyrating used a 1–4 scale: “1” � not useful, “2” � somewhat useful, “3”� useful, and “4” � extremely useful. The four SIPs were comprisedof second-year medical student teaching assistant program (TA), di-rected study program (DS), weekly instructor laboratory reviews (IR),and web-based anatomy program (WP). *Significant difference (P �0.05) between WP and IR.

326 Forester et al.

that some students did not attempt to use the WP,however, which may explain why it was ranked as“least beneficial.”

Researchers (Yeager and Young, 1992; Sawyer etal., 1996; Nnodim, 1997; Hallgren et al., 2002; Op denAkker et al., 2002) have reported that supplemental/alternative teaching methods have positive effects onstudents’ learning. Likewise, the current study foundthat students who received the four supplementalinstruction programs (Experimental Group) per-formed significantly better on both the back-upperlimb and lower limb portions of the gross anatomylaboratory practical than those students who did notreceive the supplemental instruction (Control Group;Fig. 1). An alternate explanation for the study’s resultsis that an a priori difference in academic achievementexisted between the Control and Experimentalgroups.

To investigate whether the two groups differedacademically, we obtained several mean academicvariables from the Admission’s Department at UHS-COM. The average undergraduate GPA for the Con-trol and Experimental groups was 3.47 and 3.46, re-spectively. Undergraduate science GPA for theControl and Experimental groups was 3.35 and 3.34,respectively. The average MCAT score for bothgroups was the same, 8.1. Collectively, these dataindicate academic homogeneity between the twogroups, supporting the study’s treatment or indepen-dent variable (i.e., four SIPs) to appropriately assessthe study’s yield or dependent variable (i.e., grossanatomy laboratory practical performance).

As medical schools continue to search for and im-plement the best possible curriculum, anatomistsmust remain open to developing and using alterna-

tive/supplemental methods for teaching anatomy.The four supplemental instruction programs de-scribed in this study improved students’ learning ofhuman anatomy as measured by laboratory practicalperformance. Of the four SIPs, student surveys indi-cated that additional time in the laboratory with theinstructors was extremely useful and most beneficialto students.

ACKNOWLEDGMENT

The authors would like to thank Ms. Nancy L.Stroud, UHS-COM Interlibrary Loan Specialist, forretrieving and compiling manuscript references.

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TABLE 3. Student Survey Ranking for the FourSupplemental Instruction Programsa

Supplementalinstructionprogram

Responses n (%)

1 2 3 4

TA 40 (23.5) 42 (24.7) 46 (27.1) 42 (24.7)DS 30 (17.6) 55 (32.3) 53 (31.2) 32 (18.9)IR 63 (37.0) 42 (24.7) 37 (21.8) 28 (16.5)WP 37 (21.8) 32 (18.8) 33 (19.4) 68 (40.0)

aTotal number of responses � 170. The student survey rankingused a 1–4 scale: 1, most beneficial; 2, second most beneficial; 3,third most beneficial; 4, least beneficial. The Supplemental In-struction Programs were: TA, second-year medical student teach-ing assistant program; DS, directed study program; IR, weeklyinstructor laboratory reviews; WP, web-based anatomy program.

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