Students enter baccalaureate nursing programs with varying degrees of mathematical ability. Some students seem to have a sound mathematical base. Others are less fortunate. The apparent decline in recent SAT scores raises the question of instructional validity, at least for high schools. Somehow, nursing faculty must bring all students to a satisfactory level of competence in dealing with mathematical concepts. The task for faculty becomes more complicated when an integra ted curriculum exists.
In addition, the transition to unit dose packaging of medication in clinical facilities reduces the need for frequent dosage calculation. Unfortunately, "disuse makes for misuse," so that the demands become greater when a nurse has to calculate a drug dosage. "Incident reports of medication usually detail only errors of administration" while errors of dosage calculations may go undetected.1 Thus, the considerations of accountability and a high level of quality nursing care are in full view to nurses who are practicing in a society where the use of medications continually increases, in part because American people are generally living longer and are being maintained on drug therapies.
Nurse educators have to decide when to introduce posology, the study of dosage calculations, and what are the most effective methods for introducing and integrating these concepts.
We approached the study of posology for an integrated curriculum in an orderly, systematic way. Through the use of the nursing process, we made an assessment concerning the nature and extent of the problems in teaching posology. Strategies for implementation were planned, and initial intervention occurred early in the curriculum. An evaluation summarized the effects of initial implementation of the program.
We approached the issue of better preparing students in posology within an integrated curriculum by going back to basics. An assessment of the scope and extent of the existing problem was undertaken by using formal and informal communications collected from faculty and students.
Sound educational principles involved the area of faculty concerns. The sequencing of posology was within a busy acutecare unit. This often did not allow for adequate demonstration of newly acquired skills and acted as a barrier to higher learning levels of pharmacology. Students were concerned with their inability to recall or utilize high school mathematics necessary to master posology. What was previously sufficient to meet student needs had a failure rate of about ten percent with contemporary students in today's curriculum.
Optimal utilization of faculty expertise was accomplished by working through problems of curriculum placement and the identification of student body characteristics. The coordinator's involvement with the curriculum committee and her awareness of the needs of modern students were invaluable at this time. Two decisions were reached in hopes of lowering the failure rate. Posology needed to be introduced earlier in the program to allow for expansion of knowledge on higher levels. Also, students needed content which would bridge the gap between fundamental mathematics and complex dosage problems.
Plan: Developing the Module
A self -learning packet was developed for first level nursing students. Because these students were younger and less sophisticated in their analytical thinking, the content focused on the application level of cognition.
Then, the teaching and learning strategy of a self-directing, self-correcting, selfpacing module was outlined.2 The concept attainment model employs an inductive process whereby basic concepts were presented from which the learner could build. Beginning with a foundation of mathematics (decimals, fractions, ratio and proportion, and percentage), the student could follow a line of logical reasoning to solve accurately dosage calculation problems.
The following are the terminal objectives developed to reflect the level of the student and the selected teaching and learning mode.
1. Define terms appearing on the Vocabulary List.
2. Solve realistic problems in five areas of mathematics.
3. Distinguish between each system of measurement.
4. Interpret abbreviations and symbols commonly used when calculating dosages.
5. Convert from one system of measurement to another.
6. Sol ve dosage problems correctly contributing to the utilization of the nursing process.
7. Analyze own progress by using the practice problem section of the module.
The self-contained packet was divided into six units of information (represented by objectives one through six) and a practice problem section followed each unit, enabling the learner to meet the seventh and final objective. This method of allowing for practice gives the student the opportunity to identify problems in one area before advancing to a more difficult one. Success with these problems may also create incentive to proceed. A comprehensive answer sheet included processes used in obtaining answers which allows for appropriate analysis of progress.
The Table of Specifications: After outlining content and learning outcomes, a table of specifications was prepared. What we wanted to be certain of was that any examination constructed would approximate the amount of material covered in the module. In addition, the table provided assurance that a test would measure an equal proportion of learning outcomes.
As seen in Table I, the module content is broken down into five sections and compared to outcomes according to the level of cognitive domain. Only the knowledge, comprehension, and application levels of cognitive domain were used. Those numbers appearing under the levels of cognitive domain indicate the total sum of multiplechoice test questions for that area. For example, six questions on the examination will measure knowledge of terms, two of them pertain to vocabulary, two to the apothecary system, one to the metric system, and one to the household system. The use of a Table of Specifications enabled us to construct a test which would mirror the module content and represent an appropriate level of cognitive domain.
A pre-test was administered during the first week of the semester to assess the students' knowledge prior to any formal exposure to posology. An outline for the subsequent laboratory sessions was based on this initial assessment. Because no grades were assigned to the pre-test which eliminated a major source of motivation, it was hoped that the examination itself would provide student incentive.
Laboratory sessions were held two weeks after the pre-test and distribution of the posology module. Each informal session of fifteen to twenty students facilitated verbal feedback and allowed for a more accurate assessement of knowledge attained.
Although the laboratory sessions were early in the semester and early in the day, these possible constraints did not seem to affect student performance. The students displayed motivation and spontaneity through their responses which reflected their value for the subject matter. As adult learners, they were perceptive in questioning a few typographical errors rather than merely accepting the written word as true. Also, a quest for more information was demonstrated by the question, "What is the exact translation of the symbol ss?"
The major focus of the laboratory sessions was to resolve any problems concerning the posology module and to provide additional opportunity for dosage calculation. Use of available audio-visual aids supported our effort to reinforce basic concepts. For example, realistic problems were given to assess the students' ability to apply knowledge obtained, and syringes and medication cups were available for a "hands-on" experience.
A voluntary ex tra -help session was scheduled to resolve any student difficulties. Only 1 of 77 students attended the session. This was a minority student from a country other than the United States.
The administration of a post-test concluded the planned intervention phase.
The answer sheets for both the pre- and post-tests were computer-scored. An item analysis revealed the Kuder-Richardson reliabilities were 0.71 and 0.69, respectively.
The model of pre-post measurement of performance allowed for comparison of test scores (Figure 1). The results of the pre-test were a mean of 52 and a range of 48 (low = 33; high = 81) compared to the post-test mean of 92.7 and a range of 24 (low = 76; high = 100).
This comparison provides initial evaluation of our intervention. As students progress through the curriculum, their performance can provide continual evaluation of the effectiveness of the posology program.
Introduction of the posology module has set a precedent for further intervention in this integrated curriculum. The second level nursing course has begun to incorporate the calculation and administration of intravenous solutions and is followed by a comprehensive study of pharmacology and posology applicable to the acute care setting. An outline of intervention proposed for the final level nursing course includes the long-term use of drugs, initial and maintenance dosages, and drug toxicity.
TABLE OF SPECIFICATIONS FOR A SUMMATIONAL TEST IN POSOLOGY
BAR GRAPH OF PRE- AND POST-TEST SCORES
Faculty and student input through written and verbal feedback indicated a highlevel acceptance of the posology program.
We used an organized problem-solving method to resolve posology problems in an integrated curriculum. A thorough assessment of the extent of problems revealed the need for a mathematical foundation (perhaps due to decreased mathematics SAT scores) to achieve a high level of accuracy with posology in preparation for professional nursing practice. Early curriculum intervention allowed for higher learning level achievement and sufficient time for demonstration of acquired skills. The implementation of a self -learning module in conjunction with small group intervention appeared to have an impact on students' level of knowledge as well as the application of knowledge. This was evidenced by an increased mean score from pre- to post-testing on a multiple-choice examination. Ongoing evaluations will measure students' ability to actualize these concepts in their clinical practice.
Perhaps now is the time to identify posology within integrated curricula and examine it as a basis for pharmacology to better prepare all students for this vital nursing responsibility.
- 1. Del Buono DJ: Verifying the nurses' knowledge of pharmacology. N «rs Outlook 20:463, July 1972.
- 2. Cyrs TE Jr: How to design learning modules. J Prac Nun 26:30 September 1976.
- 3. Gronlund N: Construction Afhierement Tesis. Englewood Cliffs, NJ, Prentice- Hall, Ine, 1977, p 27.
TABLE OF SPECIFICATIONS FOR A SUMMATIONAL TEST IN POSOLOGY