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Nutritional Knowledge and Attitudes of Dental Students
a r t ic l e s
Nutritional knowledge and attitudes of dental students Carol L. Pietz, M S, RD Beth A. Fryer, PhD, RD Holly C. Fryer, PhD
As recent studies have indicated that know ledge of nutrition m ay be inadequate among som e groups in the m edical and dental professions, a survey was m ade o f first-year and fourth-year dental students to determ ine their know ledge, attitudes, and source of information about nutrition.
P
.M. rev en tio n is a key w ord in m o d ern d en tistry , and one of th e co m p o n ents of p rev en tiv e d ental care is n u tritio n . In re ce n t y ears, d ietary and n u tritio n a l c o u n s e lin g and h ealth screen in g have b eco m e in creasin gly im p ortan t in th e p rov isio n of c o m p reh en sive d en tal c a r e .1,2 The em p hasis on reg u lar d ental checku p s puts the d en tist in a u n iq u e position am o n g m em bers o f th e h ealth care p rofession s. In co n trast w ith oth er h ealth p rofession als w h ose p ractices m ain ly in volve ill p erson s, the d en tist ty p ica lly sees h ealth y patients on a reg u lar, p erio d ic basis. This situ a tion p rov id es m an y op p ortu n ities for h ealth screen in g an d n u tritio n ed u catio n . If th e d en tist is to fu n ction effec t i v e l y in th e c o m p l e x ro le o f a m o n ito r of n utrition al h ealth and an ed u ca to r, he or sh e m u st h ave a th o r ou gh u n d erstan d in g of n orm al and th erap eu tic n u tritio n an d an aw are n ess of the co m m o n m isco n cep tio n s p rom oted by som e of the p o p u lar lit e r a tu r e . H o w e v e r, r e c e n t s tu d ie s h ave in d icated th at k now ledge of n u tritio n m ay b e in a d e q u a te a m o n g som e grou p s in the m ed ical and d en tal p rofession s.3'7 A k st an d o th e rs 8 s u rv e y e d 3 4 7 d e n tists in th e U n ite d S tates and 366 ■ I ADA, Vol. 100, March 1980
C an ad a an d fo u n d th a t, a lth o u g h m ore than 9 8 % said th ey p racticed p reven tive d en tistry, less th an 2 0% p erfo rm ed an y ty p e of n u tritio n al an alysis or d ietary evalu ation of th eir p atients. C o nversely, som e d entists h a v e in co rp o rated e x ten siv e n u tri tio n a l e v a lu a tio n an d c o u n s e lin g p ro g ra m s in to th e ir p r a c t ic e s .910 H ow ever, som e p rogram s of this type h ave b een q u estio n ed .11 T h e n u tritio n al k now ledge and at titu d es of to d a y ’s d en tal stu d en ts are of in te re st b e ca u se th e y are in d i cato rs of th e n u tritio n al skills of to m o rro w ’s d entists. T h e k n ow led ge acq u ired and the attitu d es form ed by th e dental stu d en t w ill be carried w ith h im o r h er in to p ro fessio n al p ra c tic e an d w ill u ltim ately in flu en ce th e q uality of p reven tive d en tal care d elivered to patients. T h is stu d y w as c o n d u cted to assess th e n u tritio n al k n o w led g e an d a t titud es o f first- an d fo u rth -y ear stu dents at th e S ch oo l o f D entistry at th e U n iv ersity of M issouri-K an sas City.
M eth o d s A q uestion n aire to assess k n ow led ge of n u tritio n and attitud es tow ard v ar ious asp ects of n u tritio n and ca re of p atients w as d ev elo p ed , rev iew ed ,
and p retested . S om e tru e-false q u es tions about k now ledge of n u tritio n w ere selected from a q u estion n aire fo r p h y s ic ia n s .3 A d d itio n a l q u e s tion s w ere co n stru cted sp ecifically for this study; th ey w ere b ased on cu rren t em p h ases in th e d en tal an d n u tritional scien tific literatu re. Sub je c t m a tte r in c lu d e d n o rm a l an d th e ra p e u tic n u tritio n , d iets, food s, n u tr ie n ts , n u tritio n an d d e n ta l h ealth , and n utritio n al assessm en t. Th e q u estion s w ere rev iew ed by tw o facu lty m em bers in th e d ep artm en t of foods an d n u trition at K ansas S tate U n iv ersity and on e facu lty m em b er in th e d ep artm en t of b io ch em istry and n u tritio n at the S ch o o l of D en tistry at th e U n iv ersity of M isso u riK ansas C ity. R evisions w ere m ad e based on th eir reco m m en d atio n s and a m easu rin g in stru m en t w as d ev el o p e d an d p r e te s te d . A t t i tu d i n a l s t a te m e n t s w e r e d e v e l o p e d , r e view ed , and p retested in the sam e m an n er as the q uestion s reg ard in g k now ledge. T h e re fin e d q u e s tio n n a ire c o n sisted of a form d esig n ed to g ath er b ack grou n d in form ation ab ou t the sub ject (age, gen d er, year in d ental s c h o o l, e d u c a tio n a l b a c k g r o u n d , n u tritio n -re la te d w ork e x p e rie n c e , and s o u rc e s of n u tritio n in fo rm a tion ), a 50-q u estion test of n u tritio n al k now ledge, an d a 15 -sta te m e n t a t ti tu d in a l s u r v e y . F o r th e t e s t o f k now ledge, the stud ents resp on d ed to the 5 0 statem en ts by an sw erin g “ tru e ,” “ false,” or “ u n c e rta in ” an d in d icated th eir d egree of ce rta in ty for each resp on se. A five-p o in t sca le w as u sed for d egree of certain ty . Q u es tion s w ere sco red as follow s: th e re sponses w ere scored as c o rre ct o r in c o rre ct on a scale of 1 to 8, ran g in g from + 1 to + 8 for co rre ct resp o n ses
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(slightly certain to highly certain) and —1 to —8 for incorrect responses. A response of “uncertain” received a score of zero. The maximum and minimum possible scores were +400 and -4 0 0 , respectively. For the nutrition attitude survey, students indicated their strength of agreem ent with the attitudinal statements by responding “strongly agree” (SA), “agree” (A), “unde cid e d ” (U ), “ d isag ree” (D), or “strongly disagree” (SD). Statements for which agreement indicated a fa vorable attitude toward nutrition were scored + 5 for SA, + 2 for A, 0 for U, - 2 for D, and - 5 for SD. State ments for which disagreement indi cated a positive nutrition attitude were scored —5 for SA, - 2 for A, 0 for U, +2 for D, and +5 for SD. An over all nutrition attitude score for each student was obtained by summing the points made on each attitudinal statem e n t. The m axim um and minimum possible scores were +75 and —75, respectively. The higher the nutrition attitude score, the more positive the attitude toward nutri tion. The reliability (internal consis tency) of the measuring instrument was computed using Cronbach’s formula for coefficient alpha (a), as d e s c r ib e d by M e h re n s an d Lehmann.12 Coefficient alpha is a g e n e ra liz a tio n of th e K u d erRichardson Test (KR-20) used when scoring of test items is not just dichotomous (right or wrong) but in cludes an additional dimension based on degree of certainty. The a for the nutritional knowledge test was .611, which was somewhat low but acceptable. The a for the attitude survey was .753, which indicated good reliability. All students who were members of the first- and fourth-year classes at the School of Dentistry at the Univer sity of Missouri-Kansas City during the winter semester of 1979 were asked to participate in this research project. The first-year students had just completed their only formal nu trition course in dental school. Their nutritional knowledge and attitudes were products of both their formal training and their previous experi ences with nutrition. The fourth-year students had been further influenced by the remainder of the dental school curriculum plus clinical dental expe
rience during the third and fourth years of dental school. The sample was obtained by ad ministering the measuring instru ment to each group of students dur ing a regularly scheduled class period; it was believed that this pro cedure would yield a higher rate of return than a mail survey. Students who were absent from class on the day of the data collection were not included in the study. Of the 316 total members of the two classes, re sponses were received for 2 3 7 ; usable data were obtained from 230 ques tionnaires.
Results Responses were received from 97 first- and 133 fourth-year dental stu dents. All of the students were 20 to 40 years old; most were 20 to 30 years. Ten percent of the students in the sample were women. More than two thirds (68%) of the students had majored in the biological sciences be fore admission to dental school, with smaller numbers having studied the physical and social sciences and humanities. Eighty-seven percent had earned only a bachelor’s degree before dental school, 6.1% had earned a higher degree, and 6.5% had no earlier degree. Classes in dental school were re ported by students as major sources of nutrition information, as were tv, new spapers, texts, fam ily, and friends. Another frequently named source of nutrition information for
students was The Journal of the American Dental Association. Few students reported nutritionrelated work experiences other than those required for class assignments. Additionally, few students reported using the techniques learned in their nutrition course (diet analysis, nutri tional counseling) when working with clinic patients. The p ossible m axim um and minimum scores for the nutritional knowledge test were +400 and -4 0 0 , based on correctness of response and degree of certainty. The scores ranged from 298 to 59, with 67% of them within the range of 101 to 200 (Table 1). The mean score of first-year students was significantly higher (P < .001) than that of fourth-year stu dents (Table 2). No significant dif ference was found between mean scores for men and women. The mean nutritional knowledge score of 155.1 for all of the students combined was somewhat low. Over all, 68.6% of the questions were an swered correctly, as true or false, but the scores were adversely affected by the degree of certainty. Table 3 shows the percentage of correct, incorrect, and uncertain responses to the vari ous categories of nutrition knowl edge tested. In some categories, 10% to 15% of the responses were marked “uncertain.” As expected, the dental students scored highest on nutrition questions directly related to oral health and disease. More than three fourths of those questions were answered cor
Table 1 ■ Distribution of nutritional knowledge test scores. Respondents First year range 251 201 151 101 59
to to to to to
Fourth year
Total
No.
%
No.
%
No.
%
6 26 39 21 5
6.2 26.8 40.2 21.6 5.2
0 19 49 44
0.0 14.3 36.8 33.1 15.8
6 45 88 65 26
2.6 19.5 38.3 28.3 11.3
298 250 200 150 100
¿1
Table 2 ■ M ean nu tritional know ledge scores. Respondents Class First-vear students Fourth-year students Sex Men Women Total
No. students
Mean scores
97 133
183.1* 148.1
207 23 230
163.0 NSf 168.0 155.1
‘ Significantly higher, P < .001. fNS = nonsignificant.
Pietz-Fryer-Fryer : NUTRITIONAL KNOWLEDGE AND ATTITUDES OF DENTAL STUDENTS ■ 367
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rectly. Conversely, the subjects scored poorly on questions dealing with nutritional assessment tech niques; less than half (45%) were aware that analysis of hair is not, at present, refined to the point of being a reliable means of assessing the m ineral status of in d ivid u als. Slightly more than half (56%) of the students knew that analysis of a blood sample cannot determine the status of some nutrients in the body. Apparently, many of the students did not fully understand the body’s elaborate homeostatic control of some nutrients, such as calcium. Only about a fourth of the students understood that the Recommended Dietary Allowances do not represent minimum daily requirements of in dividuals. Another category of nutritional knowledge in which students scored poorly was diets. More than half of them believed that vegetarian diets were usually inadequate in protein, whereas 40% mistakenly thought that a high protein-low carbohydrate diet was ideal for weight reduction. Bozdech and others6 also reported low scores on questions related to diets among a group of dental stu dents at the University of Kentucky. The 15 statements used to deter mine nutrition attitudes are shown in Table 4. Agreement with all of the statements, except statements 9 and 13, indicated a positive attitude to ward nutrition. The overall mean at titude score was 39.1 of a possible 75 points. There were no significant dif ferences between scores of first- and fourth-year students or between men and women. Overall, there was a high degree of agreement with many of the nutrition attitudes, except for statements 7, 9, 11, 12, and 13. Nearly all of the stu dents agreed that dentists were vital members of the health care team and that good nutrition had an important role in general and dental health. Fourth-year students agreed more strongly than first-year students with the statement that nutrition should be emphasized in a dentist’s educa tional preparation. More than 95% of all the subjects supported the idea that dentists should be capable of recognizing symptoms of malnutri tion and should routinely look for them when examining patients. Ap proximately 48% of the students 368 ■ JADA, Vol. 100, March 1980
T a b le 3 ■ Percentages of correct, incorrect, and uncertain
responses to categories of nutritional knowledge. Category of knowledge
Correct (%)
Incorrect (%)
Uncertain (%)
Nutrition in oral health and disease Foods Nutrition in disease Nutrients Nutrient needs Diets Nutritional assessment
76.5 72.1 70.1 67.2 65.3 60.8 52.2
20.0 21.4 15.8 19.3 24.2 37.9 32.6
3.5 6.5 14.1 13.5 10.5 1.3 15.2
T a b le 4 ■ Nutritional attitude statements. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
Nutrition is an essential part of total health care. Dentists are a vital part of the health care team. Good nutrition is important to dental health. Nutrition should be emphasized in a dentist’s educational pre paration. Dentists should be familiar with the physical symptoms of malnutrition and should look for them in their patients. Poor oral health can adversely affect the general health of the entire body. It is a responsibility of the dentist to disseminate nutrition and dietary information to his/her patients. Dentists should know the principles of optimum nutrition and how to apply them. Dentists should recommend or prescribe nutritional supple ments for their patients. The advice of a registered dietitian or nutritionist can be very helpful to a dentist in planning nutrition education for his/ her patients. A dentist should refer any patient who has physical symp toms of malnutrition to a physician. A thorough dietary history and food recall or record should be obtained from every patient as a part of the plan of pre ventive dental care. A list of foods to avoid is adequate dietary instruction for pa tients. Proper nutrition is as important as proper oral hygiene in the prevention of oral disease. In assessing the nutritional status of a person, one must con sider his dietary habits, socioeconomic situation, blood nu trient levels, medications taken, general health, age, gender, and outward appearance.
agreed with the statement that den tists should recommend or prescribe nutritional supplements for patients. On that issue, first-year students (58%) were more likely to agree, whereas more fourth-year students (40%) were undecided. Nearly three fourths of the students agreed that dentists have a responsi bility to become involved in the nu trition education of their patients, with fourth-year students agreeing more strongly than first-year stu dents. However, 16% of both groups were undecided as to the role of the dentist in nutrition education. More than 85% of the students agreed that the advice of a registered dietitian or nutritionist could be helpful to the dentist planning nutrition education for patients. More than half of the students agreed that nutrition is just as impor tant as oral hygiene in the prevention of oral diseases. This finding was surprising in view of the emphasis in the scientific literature on oral hygiene as the primary factor in pre
vention of oral diseases. Only ap proximately a fourth disagreed with that statement. Nutritional knowledge score did not correlate with nutrition attitude score (r = -.086).
Discussion The lower nutrition knowledge scores of fourth-year students indi cated that loss of nutrition informa tion, rather than reinforcement of learning, apparently had occurred in the three years since the students had taken their only formal nutrition course. This finding suggests the need to integrate nutritional princi ples into other courses in the dental curriculum, to reinforce learning and improve retention of nutrition in formation. Although first-year stu dents scored significantly higher than fourth-year students on the nu tritional knowledge test, the score for neither group was high; they re flected considerable uncertainty about some areas of nutritional
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knowledge. Students were well informed about the relationship of nutrition to oral health and disease. In other areas, students’ knowledge was rather lim ited. Because dentists treat patients of all ages who have a variety of health problems, an understanding of the nutritional implications of cer tain stages of the life cycle and of cer tain diseases is important. Further more, a lack of knowledge of the techniques of assessing nutritional status may seriously hamper the den tist’s effectiveness in screening and treating nutritional problems of pa tients. In general, students expressed fa vorable attitudes toward nutrition. The students strongly supported the role of the dentist as a member of the health care team but were less sure of the role as a nutrition educator. This may have been a reflection of stu dents’ uncertainty about their nutri tional knowledge or may have indi cated a belief that dietitians and nu tritionists should be used more in the provision of comprehensive dental care to patients. Although opinions were diverse on the question of whether a dentist should recommend or prescribe nutritional supple ments, a surprising number of stu dents supported that practice. Sup plements are sometimes prescribed in dosages that far exceed the body’s capacity to use them as nutrients, and thus they may act primarily as chem icals. Prescription of supplements should be done only by persons who have a sound knowledge of the interrelation sh ip s of nutrients within the body and of the possible com p lication s asso ciated with megadoses. The students surveyed in this study expressed support of the den tist’s role in screening for nutritional problems. To be fully effective in this activity, however, demands a thor ough understanding of the tech niques of nutritional assessment. The results of this study indicated that more educational emphasis on this topic is needed to adequately prepare
dentists to perform this important function. The unique situ atio n of the dentist—with a clientele of healthy people seen on a regular basis— holds great potential for improved health screening. Dentists who are properly and thoroughly trained in nutrition and the appropriate tech niques for nutritional assessment have the opportunity to assume more central roles in health care than many of their colleagues currently have.
Summary The nutritional knowledge and at titudes of 230 dental students were studied. The students answered 68.6% of the nutritional knowledge questions correctly, but the test scores were low because they were adversely affected by the degree of certainty. First-year students scored significantly higher than fourth-year students. There was no significant difference between scores of men and women. Knowledge scores were highest for questions on nutrition and oral health and lowest for those on nutritional assessment. Dental students generally expressed favor able attitudes toward nutrition and nutritional care of patients. They agreed that dentists were vital mem bers of the health team and had a re sponsibility to become involved in health screening and nutrition edu cation of patients. Dietitians were seen as valuable resources to be con sulted about nutrition education of the dental patient. More first-year students supported the idea that den tists should prescribe nutritional supplements for patients, whereas more fourth-year students were un decided about this matter. There were no differences in nutrition at titude scores attributable to gender of the student or year in dental school. In this study, nutritional knowledge scores did not correlate with nutri tion attitude scores.
The informed consent of all the human sub jects who participated in the research project was obtained after the procedures had been fully explained. There were no risks or discom forts associated with the collection of data, and subjects were informed that their participation was strictly voluntary. This research was supported by the depart ment of foods and nutrition and department of statistics, Kansas State University, Agricultural Experimental Station, Manhattan (contribution no. 80-75-j). The authors thank Dr. Patricia Randolph, as sociate professor of biochemistry and nutrition, for special encouragement and advice, other faculty members for their cooperation, and the first- and fourth-year students, School of Den tistry, University of Missouri-Kansas City, for their participation. Mrs. Pietz, formerly a graduate student, Kan sas State University, is currently doing volun teer nutritional counseling in Germany. Dr. Beth Fryer is professor, department of foods and nutrition, and Dr. Holly Fryer is professor, de partment of statistics, Kansas State University, Manhattan, 66506. Address requests for re prints to Dr. Beth Fryer. 1. Nizel, A.E., and Shulman, J.S. The science and art of inhibiting caries in adolescents via personalized nutritional counseling. Dent Clin North Am 13:387-404, 1969. 2. Shank, S.E., and Guthrie, H.A. Nutritional counseling for prevention of dental caries in adolescents. JADA 92(2):378-382, 1976. 3. Krause, T.O., and Fox, H.M. Nutritional knowledge and attitudes of physicians. J Am Diet Assoc 70(6}:607-609, 1977. 4. Phillips, M.G. The nutrition knowledge of medical students. J Med Educ 46(l):86-90, 1971. 5. Vickstrom, J.A., and Fox, H.M. Nutritional knowledge and attitudes of registered nurses. J Am Diet Assoc 68(5):453-456, 1976. 6. Bozdech, P.M., and others. Assessment of nutrition education of dental students. J Am Diet Assoc 73(l):36-39, 1978. 7. Odom, J.G.; DePaola, D.P.; and Robbins, A.E. Clinical nutrition education for dental stu dents: a conjoint approach. J Am Diet Assoc 72(l):56-58, 1978. 8. Akst, H., and others. A profile of clinical preventive practice. JADA 87(19]:857-862, 1973. 9. Huggins, H.A. Balancing body chemistry for better success in dentistry. J Prev Dent l(3):24-27, 1974. 10. Huggins, H.A. Biochem ical roots in periodontal disease. CDS Rev 70:20-22,1977. 11. Council on Dental Research. Position statem en t on Hal H u g g in s d ie t. JADA 91{12}:1253, 1975. 12. Mehrens, W.A., and Lehmann, I.J. Mea surement and evaluation in education and psychology, ed 2. New York, Holt, Rinehart and Winston, 1975.
Pietz-Fryer-Fryer : NUTRITIONAL KNOWLEDGE AND ATTITUDES OF DENTAL STUDENTS ■ 369
Nutritional knowledge and attitudes of dental students Carol L. Pietz, M S, RD Beth A. Fryer, PhD, RD Holly C. Fryer, PhD
As recent studies have indicated that know ledge of nutrition m ay be inadequate among som e groups in the m edical and dental professions, a survey was m ade o f first-year and fourth-year dental students to determ ine their know ledge, attitudes, and source of information about nutrition.
P
.M. rev en tio n is a key w ord in m o d ern d en tistry , and one of th e co m p o n ents of p rev en tiv e d ental care is n u tritio n . In re ce n t y ears, d ietary and n u tritio n a l c o u n s e lin g and h ealth screen in g have b eco m e in creasin gly im p ortan t in th e p rov isio n of c o m p reh en sive d en tal c a r e .1,2 The em p hasis on reg u lar d ental checku p s puts the d en tist in a u n iq u e position am o n g m em bers o f th e h ealth care p rofession s. In co n trast w ith oth er h ealth p rofession als w h ose p ractices m ain ly in volve ill p erson s, the d en tist ty p ica lly sees h ealth y patients on a reg u lar, p erio d ic basis. This situ a tion p rov id es m an y op p ortu n ities for h ealth screen in g an d n u tritio n ed u catio n . If th e d en tist is to fu n ction effec t i v e l y in th e c o m p l e x ro le o f a m o n ito r of n utrition al h ealth and an ed u ca to r, he or sh e m u st h ave a th o r ou gh u n d erstan d in g of n orm al and th erap eu tic n u tritio n an d an aw are n ess of the co m m o n m isco n cep tio n s p rom oted by som e of the p o p u lar lit e r a tu r e . H o w e v e r, r e c e n t s tu d ie s h ave in d icated th at k now ledge of n u tritio n m ay b e in a d e q u a te a m o n g som e grou p s in the m ed ical and d en tal p rofession s.3'7 A k st an d o th e rs 8 s u rv e y e d 3 4 7 d e n tists in th e U n ite d S tates and 366 ■ I ADA, Vol. 100, March 1980
C an ad a an d fo u n d th a t, a lth o u g h m ore than 9 8 % said th ey p racticed p reven tive d en tistry, less th an 2 0% p erfo rm ed an y ty p e of n u tritio n al an alysis or d ietary evalu ation of th eir p atients. C o nversely, som e d entists h a v e in co rp o rated e x ten siv e n u tri tio n a l e v a lu a tio n an d c o u n s e lin g p ro g ra m s in to th e ir p r a c t ic e s .910 H ow ever, som e p rogram s of this type h ave b een q u estio n ed .11 T h e n u tritio n al k now ledge and at titu d es of to d a y ’s d en tal stu d en ts are of in te re st b e ca u se th e y are in d i cato rs of th e n u tritio n al skills of to m o rro w ’s d entists. T h e k n ow led ge acq u ired and the attitu d es form ed by th e dental stu d en t w ill be carried w ith h im o r h er in to p ro fessio n al p ra c tic e an d w ill u ltim ately in flu en ce th e q uality of p reven tive d en tal care d elivered to patients. T h is stu d y w as c o n d u cted to assess th e n u tritio n al k n o w led g e an d a t titud es o f first- an d fo u rth -y ear stu dents at th e S ch oo l o f D entistry at th e U n iv ersity of M issouri-K an sas City.
M eth o d s A q uestion n aire to assess k n ow led ge of n u tritio n and attitud es tow ard v ar ious asp ects of n u tritio n and ca re of p atients w as d ev elo p ed , rev iew ed ,
and p retested . S om e tru e-false q u es tions about k now ledge of n u tritio n w ere selected from a q u estion n aire fo r p h y s ic ia n s .3 A d d itio n a l q u e s tion s w ere co n stru cted sp ecifically for this study; th ey w ere b ased on cu rren t em p h ases in th e d en tal an d n u tritional scien tific literatu re. Sub je c t m a tte r in c lu d e d n o rm a l an d th e ra p e u tic n u tritio n , d iets, food s, n u tr ie n ts , n u tritio n an d d e n ta l h ealth , and n utritio n al assessm en t. Th e q u estion s w ere rev iew ed by tw o facu lty m em bers in th e d ep artm en t of foods an d n u trition at K ansas S tate U n iv ersity and on e facu lty m em b er in th e d ep artm en t of b io ch em istry and n u tritio n at the S ch o o l of D en tistry at th e U n iv ersity of M isso u riK ansas C ity. R evisions w ere m ad e based on th eir reco m m en d atio n s and a m easu rin g in stru m en t w as d ev el o p e d an d p r e te s te d . A t t i tu d i n a l s t a te m e n t s w e r e d e v e l o p e d , r e view ed , and p retested in the sam e m an n er as the q uestion s reg ard in g k now ledge. T h e re fin e d q u e s tio n n a ire c o n sisted of a form d esig n ed to g ath er b ack grou n d in form ation ab ou t the sub ject (age, gen d er, year in d ental s c h o o l, e d u c a tio n a l b a c k g r o u n d , n u tritio n -re la te d w ork e x p e rie n c e , and s o u rc e s of n u tritio n in fo rm a tion ), a 50-q u estion test of n u tritio n al k now ledge, an d a 15 -sta te m e n t a t ti tu d in a l s u r v e y . F o r th e t e s t o f k now ledge, the stud ents resp on d ed to the 5 0 statem en ts by an sw erin g “ tru e ,” “ false,” or “ u n c e rta in ” an d in d icated th eir d egree of ce rta in ty for each resp on se. A five-p o in t sca le w as u sed for d egree of certain ty . Q u es tion s w ere sco red as follow s: th e re sponses w ere scored as c o rre ct o r in c o rre ct on a scale of 1 to 8, ran g in g from + 1 to + 8 for co rre ct resp o n ses
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(slightly certain to highly certain) and —1 to —8 for incorrect responses. A response of “uncertain” received a score of zero. The maximum and minimum possible scores were +400 and -4 0 0 , respectively. For the nutrition attitude survey, students indicated their strength of agreem ent with the attitudinal statements by responding “strongly agree” (SA), “agree” (A), “unde cid e d ” (U ), “ d isag ree” (D), or “strongly disagree” (SD). Statements for which agreement indicated a fa vorable attitude toward nutrition were scored + 5 for SA, + 2 for A, 0 for U, - 2 for D, and - 5 for SD. State ments for which disagreement indi cated a positive nutrition attitude were scored —5 for SA, - 2 for A, 0 for U, +2 for D, and +5 for SD. An over all nutrition attitude score for each student was obtained by summing the points made on each attitudinal statem e n t. The m axim um and minimum possible scores were +75 and —75, respectively. The higher the nutrition attitude score, the more positive the attitude toward nutri tion. The reliability (internal consis tency) of the measuring instrument was computed using Cronbach’s formula for coefficient alpha (a), as d e s c r ib e d by M e h re n s an d Lehmann.12 Coefficient alpha is a g e n e ra liz a tio n of th e K u d erRichardson Test (KR-20) used when scoring of test items is not just dichotomous (right or wrong) but in cludes an additional dimension based on degree of certainty. The a for the nutritional knowledge test was .611, which was somewhat low but acceptable. The a for the attitude survey was .753, which indicated good reliability. All students who were members of the first- and fourth-year classes at the School of Dentistry at the Univer sity of Missouri-Kansas City during the winter semester of 1979 were asked to participate in this research project. The first-year students had just completed their only formal nu trition course in dental school. Their nutritional knowledge and attitudes were products of both their formal training and their previous experi ences with nutrition. The fourth-year students had been further influenced by the remainder of the dental school curriculum plus clinical dental expe
rience during the third and fourth years of dental school. The sample was obtained by ad ministering the measuring instru ment to each group of students dur ing a regularly scheduled class period; it was believed that this pro cedure would yield a higher rate of return than a mail survey. Students who were absent from class on the day of the data collection were not included in the study. Of the 316 total members of the two classes, re sponses were received for 2 3 7 ; usable data were obtained from 230 ques tionnaires.
Results Responses were received from 97 first- and 133 fourth-year dental stu dents. All of the students were 20 to 40 years old; most were 20 to 30 years. Ten percent of the students in the sample were women. More than two thirds (68%) of the students had majored in the biological sciences be fore admission to dental school, with smaller numbers having studied the physical and social sciences and humanities. Eighty-seven percent had earned only a bachelor’s degree before dental school, 6.1% had earned a higher degree, and 6.5% had no earlier degree. Classes in dental school were re ported by students as major sources of nutrition information, as were tv, new spapers, texts, fam ily, and friends. Another frequently named source of nutrition information for
students was The Journal of the American Dental Association. Few students reported nutritionrelated work experiences other than those required for class assignments. Additionally, few students reported using the techniques learned in their nutrition course (diet analysis, nutri tional counseling) when working with clinic patients. The p ossible m axim um and minimum scores for the nutritional knowledge test were +400 and -4 0 0 , based on correctness of response and degree of certainty. The scores ranged from 298 to 59, with 67% of them within the range of 101 to 200 (Table 1). The mean score of first-year students was significantly higher (P < .001) than that of fourth-year stu dents (Table 2). No significant dif ference was found between mean scores for men and women. The mean nutritional knowledge score of 155.1 for all of the students combined was somewhat low. Over all, 68.6% of the questions were an swered correctly, as true or false, but the scores were adversely affected by the degree of certainty. Table 3 shows the percentage of correct, incorrect, and uncertain responses to the vari ous categories of nutrition knowl edge tested. In some categories, 10% to 15% of the responses were marked “uncertain.” As expected, the dental students scored highest on nutrition questions directly related to oral health and disease. More than three fourths of those questions were answered cor
Table 1 ■ Distribution of nutritional knowledge test scores. Respondents First year range 251 201 151 101 59
to to to to to
Fourth year
Total
No.
%
No.
%
No.
%
6 26 39 21 5
6.2 26.8 40.2 21.6 5.2
0 19 49 44
0.0 14.3 36.8 33.1 15.8
6 45 88 65 26
2.6 19.5 38.3 28.3 11.3
298 250 200 150 100
¿1
Table 2 ■ M ean nu tritional know ledge scores. Respondents Class First-vear students Fourth-year students Sex Men Women Total
No. students
Mean scores
97 133
183.1* 148.1
207 23 230
163.0 NSf 168.0 155.1
‘ Significantly higher, P < .001. fNS = nonsignificant.
Pietz-Fryer-Fryer : NUTRITIONAL KNOWLEDGE AND ATTITUDES OF DENTAL STUDENTS ■ 367
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rectly. Conversely, the subjects scored poorly on questions dealing with nutritional assessment tech niques; less than half (45%) were aware that analysis of hair is not, at present, refined to the point of being a reliable means of assessing the m ineral status of in d ivid u als. Slightly more than half (56%) of the students knew that analysis of a blood sample cannot determine the status of some nutrients in the body. Apparently, many of the students did not fully understand the body’s elaborate homeostatic control of some nutrients, such as calcium. Only about a fourth of the students understood that the Recommended Dietary Allowances do not represent minimum daily requirements of in dividuals. Another category of nutritional knowledge in which students scored poorly was diets. More than half of them believed that vegetarian diets were usually inadequate in protein, whereas 40% mistakenly thought that a high protein-low carbohydrate diet was ideal for weight reduction. Bozdech and others6 also reported low scores on questions related to diets among a group of dental stu dents at the University of Kentucky. The 15 statements used to deter mine nutrition attitudes are shown in Table 4. Agreement with all of the statements, except statements 9 and 13, indicated a positive attitude to ward nutrition. The overall mean at titude score was 39.1 of a possible 75 points. There were no significant dif ferences between scores of first- and fourth-year students or between men and women. Overall, there was a high degree of agreement with many of the nutrition attitudes, except for statements 7, 9, 11, 12, and 13. Nearly all of the stu dents agreed that dentists were vital members of the health care team and that good nutrition had an important role in general and dental health. Fourth-year students agreed more strongly than first-year students with the statement that nutrition should be emphasized in a dentist’s educa tional preparation. More than 95% of all the subjects supported the idea that dentists should be capable of recognizing symptoms of malnutri tion and should routinely look for them when examining patients. Ap proximately 48% of the students 368 ■ JADA, Vol. 100, March 1980
T a b le 3 ■ Percentages of correct, incorrect, and uncertain
responses to categories of nutritional knowledge. Category of knowledge
Correct (%)
Incorrect (%)
Uncertain (%)
Nutrition in oral health and disease Foods Nutrition in disease Nutrients Nutrient needs Diets Nutritional assessment
76.5 72.1 70.1 67.2 65.3 60.8 52.2
20.0 21.4 15.8 19.3 24.2 37.9 32.6
3.5 6.5 14.1 13.5 10.5 1.3 15.2
T a b le 4 ■ Nutritional attitude statements. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.
Nutrition is an essential part of total health care. Dentists are a vital part of the health care team. Good nutrition is important to dental health. Nutrition should be emphasized in a dentist’s educational pre paration. Dentists should be familiar with the physical symptoms of malnutrition and should look for them in their patients. Poor oral health can adversely affect the general health of the entire body. It is a responsibility of the dentist to disseminate nutrition and dietary information to his/her patients. Dentists should know the principles of optimum nutrition and how to apply them. Dentists should recommend or prescribe nutritional supple ments for their patients. The advice of a registered dietitian or nutritionist can be very helpful to a dentist in planning nutrition education for his/ her patients. A dentist should refer any patient who has physical symp toms of malnutrition to a physician. A thorough dietary history and food recall or record should be obtained from every patient as a part of the plan of pre ventive dental care. A list of foods to avoid is adequate dietary instruction for pa tients. Proper nutrition is as important as proper oral hygiene in the prevention of oral disease. In assessing the nutritional status of a person, one must con sider his dietary habits, socioeconomic situation, blood nu trient levels, medications taken, general health, age, gender, and outward appearance.
agreed with the statement that den tists should recommend or prescribe nutritional supplements for patients. On that issue, first-year students (58%) were more likely to agree, whereas more fourth-year students (40%) were undecided. Nearly three fourths of the students agreed that dentists have a responsi bility to become involved in the nu trition education of their patients, with fourth-year students agreeing more strongly than first-year stu dents. However, 16% of both groups were undecided as to the role of the dentist in nutrition education. More than 85% of the students agreed that the advice of a registered dietitian or nutritionist could be helpful to the dentist planning nutrition education for patients. More than half of the students agreed that nutrition is just as impor tant as oral hygiene in the prevention of oral diseases. This finding was surprising in view of the emphasis in the scientific literature on oral hygiene as the primary factor in pre
vention of oral diseases. Only ap proximately a fourth disagreed with that statement. Nutritional knowledge score did not correlate with nutrition attitude score (r = -.086).
Discussion The lower nutrition knowledge scores of fourth-year students indi cated that loss of nutrition informa tion, rather than reinforcement of learning, apparently had occurred in the three years since the students had taken their only formal nutrition course. This finding suggests the need to integrate nutritional princi ples into other courses in the dental curriculum, to reinforce learning and improve retention of nutrition in formation. Although first-year stu dents scored significantly higher than fourth-year students on the nu tritional knowledge test, the score for neither group was high; they re flected considerable uncertainty about some areas of nutritional
A R T IC L E S
knowledge. Students were well informed about the relationship of nutrition to oral health and disease. In other areas, students’ knowledge was rather lim ited. Because dentists treat patients of all ages who have a variety of health problems, an understanding of the nutritional implications of cer tain stages of the life cycle and of cer tain diseases is important. Further more, a lack of knowledge of the techniques of assessing nutritional status may seriously hamper the den tist’s effectiveness in screening and treating nutritional problems of pa tients. In general, students expressed fa vorable attitudes toward nutrition. The students strongly supported the role of the dentist as a member of the health care team but were less sure of the role as a nutrition educator. This may have been a reflection of stu dents’ uncertainty about their nutri tional knowledge or may have indi cated a belief that dietitians and nu tritionists should be used more in the provision of comprehensive dental care to patients. Although opinions were diverse on the question of whether a dentist should recommend or prescribe nutritional supple ments, a surprising number of stu dents supported that practice. Sup plements are sometimes prescribed in dosages that far exceed the body’s capacity to use them as nutrients, and thus they may act primarily as chem icals. Prescription of supplements should be done only by persons who have a sound knowledge of the interrelation sh ip s of nutrients within the body and of the possible com p lication s asso ciated with megadoses. The students surveyed in this study expressed support of the den tist’s role in screening for nutritional problems. To be fully effective in this activity, however, demands a thor ough understanding of the tech niques of nutritional assessment. The results of this study indicated that more educational emphasis on this topic is needed to adequately prepare
dentists to perform this important function. The unique situ atio n of the dentist—with a clientele of healthy people seen on a regular basis— holds great potential for improved health screening. Dentists who are properly and thoroughly trained in nutrition and the appropriate tech niques for nutritional assessment have the opportunity to assume more central roles in health care than many of their colleagues currently have.
Summary The nutritional knowledge and at titudes of 230 dental students were studied. The students answered 68.6% of the nutritional knowledge questions correctly, but the test scores were low because they were adversely affected by the degree of certainty. First-year students scored significantly higher than fourth-year students. There was no significant difference between scores of men and women. Knowledge scores were highest for questions on nutrition and oral health and lowest for those on nutritional assessment. Dental students generally expressed favor able attitudes toward nutrition and nutritional care of patients. They agreed that dentists were vital mem bers of the health team and had a re sponsibility to become involved in health screening and nutrition edu cation of patients. Dietitians were seen as valuable resources to be con sulted about nutrition education of the dental patient. More first-year students supported the idea that den tists should prescribe nutritional supplements for patients, whereas more fourth-year students were un decided about this matter. There were no differences in nutrition at titude scores attributable to gender of the student or year in dental school. In this study, nutritional knowledge scores did not correlate with nutri tion attitude scores.
The informed consent of all the human sub jects who participated in the research project was obtained after the procedures had been fully explained. There were no risks or discom forts associated with the collection of data, and subjects were informed that their participation was strictly voluntary. This research was supported by the depart ment of foods and nutrition and department of statistics, Kansas State University, Agricultural Experimental Station, Manhattan (contribution no. 80-75-j). The authors thank Dr. Patricia Randolph, as sociate professor of biochemistry and nutrition, for special encouragement and advice, other faculty members for their cooperation, and the first- and fourth-year students, School of Den tistry, University of Missouri-Kansas City, for their participation. Mrs. Pietz, formerly a graduate student, Kan sas State University, is currently doing volun teer nutritional counseling in Germany. Dr. Beth Fryer is professor, department of foods and nutrition, and Dr. Holly Fryer is professor, de partment of statistics, Kansas State University, Manhattan, 66506. Address requests for re prints to Dr. Beth Fryer. 1. Nizel, A.E., and Shulman, J.S. The science and art of inhibiting caries in adolescents via personalized nutritional counseling. Dent Clin North Am 13:387-404, 1969. 2. Shank, S.E., and Guthrie, H.A. Nutritional counseling for prevention of dental caries in adolescents. JADA 92(2):378-382, 1976. 3. Krause, T.O., and Fox, H.M. Nutritional knowledge and attitudes of physicians. J Am Diet Assoc 70(6}:607-609, 1977. 4. Phillips, M.G. The nutrition knowledge of medical students. J Med Educ 46(l):86-90, 1971. 5. Vickstrom, J.A., and Fox, H.M. Nutritional knowledge and attitudes of registered nurses. J Am Diet Assoc 68(5):453-456, 1976. 6. Bozdech, P.M., and others. Assessment of nutrition education of dental students. J Am Diet Assoc 73(l):36-39, 1978. 7. Odom, J.G.; DePaola, D.P.; and Robbins, A.E. Clinical nutrition education for dental stu dents: a conjoint approach. J Am Diet Assoc 72(l):56-58, 1978. 8. Akst, H., and others. A profile of clinical preventive practice. JADA 87(19]:857-862, 1973. 9. Huggins, H.A. Balancing body chemistry for better success in dentistry. J Prev Dent l(3):24-27, 1974. 10. Huggins, H.A. Biochem ical roots in periodontal disease. CDS Rev 70:20-22,1977. 11. Council on Dental Research. Position statem en t on Hal H u g g in s d ie t. JADA 91{12}:1253, 1975. 12. Mehrens, W.A., and Lehmann, I.J. Mea surement and evaluation in education and psychology, ed 2. New York, Holt, Rinehart and Winston, 1975.
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