LSU 2006 1 Nursing Mathematics: What Skills Do Nursing Students Bring to Drug Calculations? Roslyn Gillies Learning Skills Unit Student Support Services University of Western Sydney
Transcript
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LSU 20061 Nursing Mathematics: What Skills Do Nursing Students
Bring to Drug Calculations? Roslyn Gillies Learning Skills Unit
Student Support Services University of Western Sydney
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LSU 20062 A bit about where I come from
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LSU 20063
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4 what I do
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LSU 20065 and where I do it
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LSU 20066 UWS Sydney, NSW, Australia
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LSU 20067 A bit about UWS Six campuses covering entire west of
Sydney 36 000 students 32 000 undergrads Larger campuses:
Parramatta & Penrith Smaller: Hawkesbury & Blacktown Motto:
Bringing knowledge to life Emphasis on practical courses, providing
educational opportunities for students in the region
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LSU 20068 How does Nursing Mathematics fit with
Ethnomathematics? Several definitions of ethnomathematics the study
of mathematics which takes into consideration the culture in which
mathematics arises (University of Idaho website) the mathematical
practices of identifiable cultural groups (Ubiratan DAmbrosio first
used in late 1960s)
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LSU 20069 Human activities which require some form of
mathematics Architecture - construction Weaving textiles and
baskets Sewing turning cloth/skins into clothing or shoes that fit
Agriculture calendars to mark seasons, planning for quantity and
storage, layout of gardens and fields Kinship relations
Ornamentation tilings and beadwork Spiritual and religious
practices (uidaho.edu website) and Nursing dosage
calculations!
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LSU 200610 Mathematical skills nurses require Computational
skills fractions, decimals, percentages, ratio, measurement,
conversion between units Conceptual Skills- ability to: set up the
problem for calculation apply an appropriate solution method
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LSU 200611 The culture and tradition of teaching drug
calculation Early 1980s Florence Nightingales hospital-trained
apprentice system was replaced by higher education training
Occurred in countries such as: UK Canada USA Australia New
Zealand
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LSU 200612 Impacts of this change Big bang curriculum
revolution rather than incremental change Emphasis on intellectual
and higher- level thinking skills, problem solving Mastery of basic
principles rather than facts Less time in clinical practice
situation
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LSU 200613 Other factors affecting drug calculation instruction
Increasing student diversity Multidisciplinary nature of nursing
maths (maths applied in a nursing context) Medication calculation
frequently a stressful task performed on the ward No clear policy
on whose responsibility it is to develop and maintain nurses drug
calculation competence Little agreement on teaching methods
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LSU 200614 Other factors (cont.) Assumption that maths skills
taught in the abstract will be successfully transferred to nursing
context Some nursing educators admit to poor maths skills and
difficulty in teaching drug calculations Limited opportunities for
students to practice drug calculation skills Reliance on formula
methods that do not always result in students retaining skills
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LSU 200615 The tradition of using formula methods for drug
calculation Widespread use of formula methods Examples of formulae
taught: Volume required to deliver a given mass: (Gatford &
Phillips, 2002, p. 44)
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LSU 200616 Another formula taught Drip rate for Intravenous
Infusion: (Hext & Mayner, 2003, p. 80)
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LSU 200617 Why are formulae taught? to bypass the need to
appropriate or understand any mathematical structure and to impose
consistency on what were seen to be dangerous variations in
strategy (Hoyles et al., 2001, p. 13)
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LSU 200618 The dilemma Advantages of formula methods
Standardised methods: one-size- fits-all Easy to apply Plug in the
numbers and turn the handle to get the answer Dont need to think
too much
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LSU 200619 Disadvantages of formula methods Little use of
students existing problem- solving skills Encourage belief that
drug calculation is a separate branch of mathematics Do little to
encourage students to think through the problem and understand the
calculation method Do little to encourage estimation and checking
strategies to ensure calculated dosage is reasonable
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LSU 200620 What the literature says Some students find formulae
difficult to use correctly Formulae may be a cause of conceptual
errors Formula methods are frequently ineffective and result in:
poor skill development poor retention of skills
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LSU 200621 What the literature says (cont.) In workplace
situations nurses make little use of formulae learnt Instead,
nurses use a variety of correct proportional reasoning methods that
preserve the meaning of the problem situation (Hoyles et al.,
2001)
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LSU 200622 The study Subjects: 35 recently enrolled first year
B Nursing students at UTS Instruments: Test 10 calculations (see
OHT) set in everyday contexts designed to parallel typical drug
calculation problems Questionnaire demographic data
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LSU 200623 Problem types simulated in test Calculate: Number of
tablets to deliver a given mass Volume required to administer a
given mass, either: orally by injection Intravenous medications:
drip rate (drops per minute) time to run the infusion
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LSU 200624 Some of the questions PRT item 4. A 12.5 kilogram
bag of flour lasts a cook 5 days. How many days will 45 kilograms
of flour last the cook? Parallel DCT item 4. On hand is Benadryl
12.5 mg per 5 mL. How many millilitres will you give if Benadryl 45
mg is ordered?
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LSU 200625 PRT item 5. An automatic drip feeder installed in an
aviary is to deliver 600 millilitres of water to the birds every 10
hours. If the feeder delivers 60 drops per millilitre, how many
drops are delivered each minute? Parallel DCT item 5. An
intravenous drip is to deliver 600 mL of normal saline over 10
hours. If the giving set delivers 60 drops per mL, what is the drip
rate in drops per minute?
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LSU 200626 PRT item 7. A dripping kitchen tap loses 1 litre of
water over 8 hours. It is established that 15 drops of water is
equivalent to 1 millilitre. Calculate in drops per minute the rate
at which the tap is losing water. Parallel DCT item 7. A patient is
ordered 1 litre of normal saline over 8 hours. The intravenous
giving set delivers 15 drops per mL. Calculate the drip rate in
drops per minute?
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LSU 200627 PRT item 10. A car travelling on a country road is
losing water from the radiator at the rate of 25 drops per minute.
The driver uses his last 600 millilitres of water to top up the
radiator. How long will it take for this amount to leak out if 20
drops of water is equivalent to 1 millilitre? Parallel DCT item 10.
An intravenous giving set is delivering an infusion at the rate of
25 drops per minute. The patient is to have 600 mL of Hartmanns.
How long will the infusion take if the giving set delivers 20 drops
per mL??
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LSU 200628 Research questions Before being exposed to drug
calculation instruction of special formulae: How well do students
perform on tasks similar to drug calculations? How successful are
students in applying appropriate problem-solving methods to set up
the problem for calculation? What are the native methods used by
students to solve such problems?
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LSU 200629 Scoring two methods Method 1 right/wrong test mark
out of 10 Method 2 score/3 for each item test mark out of 30 1
mark: some progress 2 marks: correct method used 3 marks correct
method and correct answer
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LSU 200630 Student profile Female: 94% Ages: 17-48 mean 25.6
(sd 7.7) Mathematics backgrounds: NSW HSC-level mathematics: 78%
Year 10 (junior high) maths or less: 20% Maths studied after
leaving school: 9% NESB Language background: 12%
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LSU 200631 Mean score Method 1 (score/10) Mean score: 3.65 (sd:
2.25) Method 2 (score/30) Mean score: 15.17 (sd: 7.57)
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LSU 200632 Pass requirement: 80% correct Method 1: (score 8/10)
Pass:11% of students Fail:89% Method 2: (score 24/30) Pass:17%
Fail:83%
LSU 200634 Deficits in students skills Inability to set up
problem for calculation (Blais & Bath, 1992; Rutherford, 1996)
Computational errors (Gillies, 1994; Gillham & Chu, 1995)
Errors in metric conversions (Rodger & Jones, 2000)
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LSU 200635 Some of the problem-solving methods students used
Division operations Unitary method and adaptations Fraction of a
quantity Proportion (formal set up) Ratio Proportional reasoning
Rewrite rate in equivalent form
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LSU 200636 No of items where correct method applied
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LSU 200637 Ability to apply correct method On average, another
1.4 Qs per student where correct method used For 26% of students, a
further 3-4 Qs where correct method used For 40% of students, at
least 2 additional Qs where correct method used
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LSU 200638 Items of particular interest Those with greatest
difference between % of students obtaining correct answer and %
using correct methodItems 4, 5, 7, 10 ie many more students can
apply a correct method than can get the correct answer These
include all three IV infusion problems traditionally most difficult
Qs For these items, high incidence of causes, other than conceptual
difficulties, that prevent success viz computational
difficulties
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LSU 200639 Item 5 Melikas working
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LSU 200640 Item 5 Nicolas working
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LSU 200641 Item 5 - Summary Key to success: Being able to
convert: ml to drops hours to minutes Being able to express stated
drip rate in appropriate equivalent forms
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LSU 200642 Item 7 Cates working
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LSU 200643 Item 7 Alisons working
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LSU 200644 Item 7 Melikas working
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LSU 200645 Item 7 Karens working
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LSU 200646 Item 7 - Summary Simplest process: Change ml to
drops early Leave conversion of hours to mins until the end
(otherwise large numbers result) Also valuable was the ability to
express division in fraction form and cancel down (avoids long
division)
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LSU 200647 Item 10 Karens working
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LSU 200648 Item 10 Melikas working
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LSU 200649 Item 10 - Summary Both students used same method
Both had difficulty in arithmetic processes: Karen gained a zero is
division (2-step process) Melika lost a zero in same division (long
division)
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LSU 200650 What analysis of students working suggests
Difficulties with IV problems are not always because of conceptual
difficulties Many students able to set up problem and apply
appropriate method Having applied an appropriate method, poor
conceptual skills may prevent progress to correct answer
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LSU 200651 Conclusions On average, students able to apply
correct method to half of the 10 items even before any drug
calculation instruction Many students fairly well equipped to deal
with even the most difficult drug calculation problems (IV
problems) Methods students use involve multiple steps that preserve
meaning of problem (Hoyles et al., 2001) When correct method
applied, incorrect answers caused by poor arithmetic skills
(Gillham & Chu, 1995; Cartwright, 1996)
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LSU 200652 Recommendations for nursing educators Need to
reassess the appropriateness of focus on teacher-taught formulae
for drug calculations Avoid killing off students existing
problem-solving skills Avoid fostering the belief that drug
calculation is a separate and unrelated branch of maths Encourage
students who prefer to use native methods and assist them in
refining those methods
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LSU 200653 Recommendations cont. If formulae taught, ensure
development of understanding: Unravel the multiple steps embodied
in the formula Stress these steps may be performed separately
Encourage students to think flexibly and apply a range of
problem-solving methods leads to mathematically powerful students
(Schoenfeld, 1992) Further research needed in areas such as: the
conceptual skills of nursing students students native
problem-solving methods and how they might apply them to drug
calculation