pbl and basic sciences

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The role of basic sciences in a problem-basedlearning clinical curriculum

P A O'Neill

Background Very little is known about the use of

problem-based learning (PBL) during the later years of

the undergraduate medical course and how it inuences

further acquisition of basic science knowledge. Simi-

larly to many other Faculties, the PBL approach is used

at Manchester in years 1 and 2, but more unusually, the

curriculum continues to be centred on PBL in the

clinical modules.

Objectives To explore whether and how basic sciencelearning was continued in year 3 of the PBL clinical

curriculum.

Methods 10 of the weekly problems from the two core

modules in year 3 were analysed to determine: (a)

whether the design teams were using basic science

objectives in devising the problems, and (b) whether

PBL student groups were setting basic science learning

objectives. The basic science knowledge of year 3 and 4

students was also measured.

Results Similar numbers of objectives were being set by

the management groups for each weekly problem

(Heart, lung and blood (HLB) module, median 15,range 1120; Nutrition, metabolism and excretion

(NME) module, median 13, range 921). In the basic

sciences, there was a median of 3 objectives per prob-

lem (range 06) in the NME module, but only 1

objective (02) per problem in the HLB module.

The objectives set by six PBL groups in each module

were analysed. Overall, agreement was reached on 130

occasions (62%) between the design team basic

science objectives and those set for themselves by the

student groups. In addition, there was a median of 2

(range 18) new basic science objectives brought out by

the PBL groups that were not listed by the HLB

module design team. In the NME module, there was

again a median of 2 new objectives (range 06). The

performance of year 3 and year 4 students in the

multiple-choice questions progress test was analysed.

For the 65 basic science questions, the year 3 mark was

408 123% compared with 571 123% for year 4

(P < 00001).

Conclusions (a) The design teams are setting basic sci-

ence objectives; (b) the working problems are triggering

students to set learning objectives in the basic sciences;

(c) most of the objectives being set by the design teams

are being triggered in the majority of group sessions;

(d) the students knowledge of basic sciences increases

in years 34.

Keywords *Curriculum; *education, medical, under-

graduate; problem-based learning.

Medical Education 2000;34:608613

Introduction

The new Manchester curriculum, which started in

1994, is integrated and uses problem-based learning in

all the core modules in years 14. From year 3 onwards,

the students' base is moved from the medical school to

one of three teaching hospital sectors. This extensive

use of PBL within a clinical environment is unusual.1

In most PBL curricula, the method is conned to the

pre-clinical course. Through this approach, clinically

relevant problems are designed to be stimulating to

discuss and as vehicles for basic science learning. One

potential disadvantage is that students may become

more interested in the clinical aspects of a problem and

neglect the underlying basic science knowledge, though

this has not been formally reported. Another drawback

may be that the students, through studying diagnostic

problems, do not acquire an appropriate framework for

the continued learning of basic science. Nevertheless, in

a fully integrated curriculum, students should go on

learning about basic science as they progress through

the course, though the emphasis may lessen.2,3

In practice, there has been ongoing concern about

the role of basic science within the undergraduate

Correspondence: P A O'Neill, Faculty of Medicine, Dentistry and

Nursing, University of Manchester, Oxford Road, Manchester M13

9PT, UK

Research papers

608 Blackwell Science Ltd MED ICA L ED UCA TI ON 2000;34:608613


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curriculum, with conferences3 and editorials4 stressing

that it should not be allowed to decline. In a review

of the experience in North American schools, Sch-

midt5 found that it was much harder to integrate

basic science into the clinical curriculum than the

converse. Others have also acknowledged these bar-

riers.3

The Manchester PBL curriculum was designed to

cover a core of knowledge over years 14 through the

use of PBL. This gave the opportunity to evaluate

whether basic science learning was continuing as stu-

dents reached the later years of the course in which they

were still using PBL. A series of questions were set in

order to examine this.

1 How are basic science themes such as anatomy

represented in the objectives for the PBL cases

through years 14?

2 Did the multidisciplinary module management

groups for year 3 use basic science objectives indesigning the PBL cases?

3 In year 3, do the PBL cases trigger basic science

learning objectives in the student groups, and are

the objectives the same as the ones intended by the

module management group?

4 How does the students' knowledge of basic sci-

ence change from year 3 to year 4?

Brief description of course

The design of the curriculum and the implementation

of PBL have been described in detail elsewhere.6,7

Thecourses in years 14 are divided into core plus special

study modules, with the core themes from years 1 and 2

being revisited and developed in years 3 and 4

(Table 1). The overarching themes for year 3 are

`Heart, lung and blood' (HLB) and `Nutrition,

metabolism and excretion' (NME).

A multidisciplinary group manages each module

and they are responsible for setting the objectives for

the module and the design of the working problems.

Each of the core modules in year 3 is 14 weeks in

length with one working problem discussed each

week. These problems are built around objectives

derived from a number of `index clinical situations'

which form the core knowledge and skills of our

curriculum.8 The working problems are much

broader than any single disease; being designed to

integrate across behavioural, clinical, pathological and

basic sciences, clinical epidemiology and public

health. Our students do not have ready access to case

objectives set by the design teams, which is unlike the

practice at other schools.9

Study setting

Groups of eight students and a tutor meet twice in

7 days; initially for 1 h to discuss the problem and thenfor 15 h to discuss what they have found out. The latter

session is longer to allow the students more time to make

the connections to similar patients they have seen.

In years 3 and 4, students have long attachments

(7 weeks) to relevant clinical rms during the core

modules (see Table 1). They also spend 1 day per week

in the community under the guidance of a general

practitioner tutor. The principal difference from the

rst 2 years is that students are constantly exposed to

clinical situations and interactions with clinicians and

professions allied to medicine.

Outside of the tutorials, the students are acquiring

clinical skills and gaining ad hoc clinical experience as

well as trying to meet the learning goals set in the rst

PBL group session. The students can meet their

learning objectives by several means. In year 3, the

teaching hospitals provide resources week to week that

support the working problem. These may include

seminars/workshops/lectures, articles, anatomical

models, pathological material, radiological images,

posters and IT access.

Table 1 The design of the curriculum for years 15

Year 1: Nutrition and metabolism

Cardiorespiratory tness

Year 2 Abilities and disabilities

Life cycle

Year 3 Basic skills course 4 weeksMain module: 14 weeks

Nutrition, metabolism and excretion

(NME)

Special study module in NME 4 weeks

Main module: 14 weeks

Heart, lungs and blood (HLB)

Special study module in HLB 4 weeks

Year 4 Main module: 14 weeks

Families and children (FC)

Special study module in FC 3 weeks

Main module: 14 weeks

Cognition, special senses and locomotion

(CSSL)

Special study module in CSSL 3 weeks

`Options' (research) 11 weeks

Year 5 Elective period 8 weeks

Hospital placement 8 weeks

Hospital placement 8 weeks

Community placement 8 weeks

Consolidation period 8 weeks

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In years 3 and 4, summative assessments have been

kept to a minimum. We have introduced the `Pro-

gress test' for summative assessment of knowledge.10

This is a multiple-choice examination which encom-

passes the core knowledge that the student should

have acquired by the time of graduation. This form

of assessment is introduced in year 3; prior to this thestudents have integrated end-of-semester exams. For

the Progress test, every student (years 35) sits a

paper twice per year, which is the same for all stu-

dents. Each question is linked to an index clinical

situation and is `tagged' according to the knowledge

it is testing. Thus, the questions in an exam paper

that are linked to basic sciences could be readily

identied.

Methods

The approach used to answering the four questions set

out in the introduction was as follows.

1. Basic science themes

Anatomy was chosen as the core theme for evalua-

tion as this is the basic science which most often

gives rise to concern about its continued place in

any undergraduate curriculum. The core database on

the Faculty website (http://www.medicine.man.ac.uk)

holds all the objectives underlying the PBL cases for

years 14. Each objective is coded according to the

general theme (e.g. physiology) and detailed objec-

tive (e.g. control of gastric acid production). Usingthe database, the author recorded the number of

coded anatomy objectives for each year of the

course.

2. Are basic science objectives used in designing

the PBL cases for year 3?

The objectives used by the module design teams for the

year 3 core modules (HLB and NME) were examined.

The number of objectives was recorded and also

divided into knowledge and skills. Prior to the analysis,

a list of key words was made up to determine the

categorization of an objective and the subsequent

agreement between the design teams and the PBL

groups (e.g. structure, anatomy). If the objective could

not be coded according to the predetermined list, it was

ignored for the study.

The problems from weeks 110 were analysed; weeks

1114 were excluded because of the possible interfer-

ence with the group discussion caused by the proximity

of examinations.

3. Are basic science objectives being triggered

in the PBL groups?

The records of the group discussion of six groups from

the NME module and six groups from the HLB module

were examined. The records covered the same 10

problems as those covered in the analysis of each of themodule management groups (i.e. 120 group discus-

sions were examined). The author compared the

learning objectives from the group discussion with

those used by the module management groups, to

determine whether any basic science objectives were

set. If this was the case, then the objectives were cate-

gorized as being either (a) similar to those intended by

the design teams, or (b) different from those of the

design teams. Objectives were categorized as being

in agreement when broadly interchangeable words

appeared (e.g. `Revise the normal cardiac anatomy' was

classied as being in agreement with `Learn about the

structure of the heart').

4. Growth of basic science knowledge

The last part of the evaluation was of how the students'

knowledge of basic science changed from year 3 to year

4. The results from the basic science questions in the

Progress test (mean and standard deviation) were cal-

culated for each year cohort taking the same exam. In

this assessment, 65 of the 250 questions were speci-

cally tagged as testing basic science knowledge. Com-

parisons were made using unpaired Student's t tests.

Results

Representation of basic science themes

A total of 71 anatomy/structural objectives were used

by the module management groups over years 14. In

year 1, 21 anatomical objectives underpin the PBL

cases, compared with 20 in year 2, 17 in year 3 (divided

over the 28 cases in the two core modules) and 13

anatomical objectives in year 4.

Use of basic science objectives in designingthe PBL cases for year 3

A similar number of objectives were being set by the

management group for each problem (HLB, median

15, range 1120; NME, median 13, range 921). In the

basic sciences, there was a median of three objectives

per problem (range 06) in the NME module, but a

median of only one objective (02) in the HLB module.

Over the 20 problems, six did not use any objectives

Basic sciences and clinical PBL P A O'Neill610



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from the basic sciences in their design; ve of these

were from the HLB module. In total, there were 35

basic science objectives for these 20 problems.

Triggering of basic science objectives

in the PBL groups

Given that six PBL groups discussed each case with its

underlying basic science objectives, then the PBL

groups could be in agreement with the 35 objectives set

by the module design team on 210 occasions (6 35).

With perfect agreement, a single objective would be

identied by all six PBL groups, which happened on

ve occasions. Conversely, on one occasion, no group

brought out in the records of their discussions the basic

science objective that was intended by the design team.

Overall, agreement was reached on 130 occasions

(62%).

There was a median of 2 (range 18) new basic sci-

ence objectives brought out by the PBL groups that

could not be categorized as being the same as those

listed by the HLB design module team. In the NME

module, there was again a median of 2 new objectives

(range 06). In total, 54 new basic science objectives

were generated by the student groups.

Growth of basic science knowledge

from year 3 to year 4

In the Progress test, the total mark (from 250 multiple

choice questions) for year 3 was 310 86% compared

with 455 8

5% for year 4. For the 65 basic science

questions, the year 3 mark was 408 123% compared

with 571 123% for year 4 (P < 00001).

Discussion

In an integrated curriculum using PBL in a clinical

environment, we found that there were basic science

objectives in the dened core content for years 3 and

4, and such objectives were underlying most of the

cases designed by the module design teams for year

3. These objectives were brought out by the majority

of the student groups who also generated a greater

number of new objectives. There was also evidence of

a growth in basic science knowledge between years 3

and 4.

There are some drawbacks to the study design. The

groups studied were based in one teaching hospital, but

this should not have resulted in any bias. The analysis

was carried out by the author using judgement on what

constituted a basic science objective and whether it was

the same in the student group discussion as that set by

the module design team. Others have used a more

rigorous method to determine agreement between

raters11 and reduce possible bias. However, the author

used a list of key words drawn up prior to the study to

categorize an objective and discarded any objective in

which these were not included. In addition, the aim was

to look for general agreement rather than precisewording of a complex objective. A further drawback is

that when a student group lists a learning objective, this

is simply a statement of intent to study a particular area,

it does not mean that any work was done. It is likely,

though, that learning did take place, given the

improvement in the basic science scores in the Progress

test, even if only measured over years 3 and 4.

Our educational approach is similar to that of Dol-

mans et al.,12 who suggested that basic science concepts

should be presented in the context of a clinical prob-

lem, to encourage integration of knowledge. Although

these authors were drawing on experience of designing

cases for use in a pre-clinical course, the same principle

holds for encouraging basic science learning within a

clinical environment. In addition, we also adhere to

another of their principles in that a case should match

one or more of the Faculty learning objectives.12 In

Manchester, we want the students to cover the core

content,8 including basic science knowledge and

understanding, over years 14.

Consequently, the rst step in our analysis was to

determine whether the design teams (on behalf of the

Faculty) were setting basic science objectives. We

found some imbalance between the two modules which

we may want to correct in future, but it may be that thecases were devised to achieve other, equally important

Faculty objectives. For example, in the HLB module,

one case is centred on somatization and non-specic

chest pain. In this, it is more important to bring out the

psychological issues rather than contrive to include

basic science.

There was concordance between the Faculty and the

student objectives in 62% of the possible matches,

which was very close to the 64% reported by Dolmans

et al.11 in a study of year 2 students. Mpofu et al.13

found a much higher agreement, but their study was on

broad themes rather than specic objectives.

We also found that the student groups generated a

greater number of new basic science objectives com-

pared with the total set by Faculty. The median

values were similar in the two modules, but if a

greater numbers of cases had been studied, it might

be that the HLB module, which contained fewer

Faculty basic science objectives, might have been

shown to generate more new student objectives. This

would also be dependent on whether the design team




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was not explicitly listing basic science objectives even

though they intended the students to bring these out

in the PBL tutorials. It would also be interesting to

look at the objectives generated by student groups in

year 4 of the course, as, by this stage, the objectives

may have become much more focused on clinical

issues rather than the basic science mechanismsunderlying the case.

Other than the case design, another important vari-

able in the effectiveness of student discussion is the

expertise of the tutors. Most of our tutors were con-

sultants in the National Health Service rather than

academic faculty.6 Given that we have just introduced

PBL into a clinical environment, nearly all the tutors

were inexperienced in the process of PBL. However, in

relation to content expertise, many would have had

reasonable knowledge of basic science (e.g. radiologists,

pathologists, haematologists, and biochemists). In the

literature, there is debate about the relative importance

of process vs. content expertise of tutors,1416 though

Regehr et al.15 reported that, when using qualied

doctors as tutors, no differences between groups were

found. In Manchester, given further experience and

staff development, it is hoped that our tutors will

become more adept at bringing out the objectives that

the case is designed to trigger.

Regardless of the generation of Faculty or student

objectives, important outcomes are whether our stu-

dents' knowledge and understanding of basic science

continues to grow as they proceed through the

course. It has been reported that students' knowledge

does increase as they go into the clinical clerkships17

and that at the end of a PBL course there is little

difference in the level of basic science knowledge of

students compared with those completing a tradi-

tional course.18 In Manchester, the Progress test

results showed that the students' basic science

knowledge signicantly increased from year 3 to year

4. However, the test, as it is currently used, simply

examines recall of factual information. We are

currently looking to develop the test to assess the

application of knowledge to problems.

Our curriculum continues to develop and the feed-

back from evaluation is an important part of this pro-

cess. As part of this, the results of this study have been

fed back to the design teams. Year 3 of the new course

has run three times, and with each successive cycle we

have rened the cases on the basis of extensive student

and tutor feedback. A further issue is how to make

suitable basic science resources (written material,

workshops, seminars, practicals, computer-assisted

learning packages, etc.) available to all our students

when most are based at least 3 miles from the medical

school in year 3 and, in year 4 (and 5), much further

aeld. This is the next stage in the integration of basic

sciences throughout the course.

Acknowledgements

I would like to thank Dr Pat McArdle for all her help

and support with this project. I would also like to

express my gratitude to the Faculty of the Harvard

Macy Program which supported the development of the

work.

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Received 12 January 1999; editorial comments to authors 1 March

1999; accepted for publication 13 August 1999



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