- Email: [email protected]
Chairside Task Inventory: Self-measuring checklist of assistant utilization
Chairside Task Inventory: Self-measuring checklist of assistant utilization
Myron J. Lefcowitz,* M A , Lola M. Irelan,f P h D , and Vito Signorile,! M A , W a s h in g t o n , D C
To
m e a s u r e th e e x t e n t to w h ic h d e n t a l
a s s is ta n ts w e r e b e in g u s e d a t th e c h a ir s id e , a c h e c k lis t o f 2 0 s e le c te d tas ks w a s d e v e lo p e d . T h e c h a ir s id e ta s k in v e n t o r y p r e s e n te d o ffe r s th e i n d i v i d u a l d e n tis t a c h a n c e to assess th e d iv is io n o f la b o r in h is o w n o p e r a t o r y a n d to e v a lu a t e h i m s e lf as a m a n a g e r o f th e d e n tis t-a s s is ta n t c h a ir s id e t e a m . T h e
i n v e n t o r y c h e c k lis t
a n d s c o r in g r u le s a r e p r o v id e d .
from both dental students, or practition ers, and their assistants concerning the division of 20 chairside tasks. The checklist, however, may be of value to the individual practitioner as a means of measuring the general division of labor in his own operatory. It also may be of some use to those interested in studying the extent to which various categories of dentists and their assistants function as a chairside team. D E V E L O P M E N T O F IN V E N T O R Y
In many dental schools, experimental training programs were developed to introduce students to the use of assistants at the chairside, that is, to the fourhanded team approach. Such programs were begun in response to the need for increasing the capacity of dentists to reach more people more effectively. In evaluating these programs, the Social Studies Branch of the Division of Dental Public Health and Resources, US Public Health Service was confronted with the problem of measuring the extent to which assistants were being used at the chairside. To deal with this problem, a checklist of selected chairside tasks was developed. This checklist, or “inventory,” of chairside tasks could be self-administered. It was designed to elicit responses
The general form of the inventory was suggested by the work of Turk,1 who de veloped a similar means for measuring differences in ideas about job division between student physicians and student nurses. In consultation with several den tists in the United States Public Health Service, the development of the inventory was carried through several stages. First, a list of tasks that might be performed by either the dentist or his assistant was drawn up. Then, since the main interest was in the chairside use of assistants, ob viously irrelevant tasks were discarded. Concerning the remaining tasks, it was determined that four areas would ade quately represent the typical range of chairside services offered by a dentist in
lefcow itz and others: C H A IR S ID E TASK IN V EN T O R Y • 95
Each of the items listed b e l o w refers t o an activity which is part of a dental procedure. A. For each activity, that best applies: D D/a E A/d A N 1 2 3 4 5 6 -7 8 9 10 11 12 13 14 15
-
indicate w h o perforins the activity by circling the one alternative
Usually only the dentist More often the dentist than the assistant Usually either the dentist or th e assistant More often the assistant th a n t h e dentist Usually only the assistant Usually someone other than the dentist or the assistant
Clip sutures during surgery Cement facings and p ontics in place Prepare amalgam filling material Place matrix b a n d in retainer Retract the cheek during surgery Keep field clear during c arving of restoration Select instruments for given operation Mix cement for bases Hold impression tray in p o sition after initial set Place amalgam in cavity Keep field clear during p lacing of fillings Block impression trays Change burs and stones for cavity preparations Prepare initial impression materials for prosthetics Keep field clear during cavity preparation
D D D D D D D D D D D D D D D
D/a D/a D/a D/a D/a D/a D/a D/a D/a D/a D/a D/a D/a D/a D/a
E E E E E E E B E E E E E E E
A/ d A/ d A/ d A/ d A/ d A/ d A/d A/d A/d A/d A/d A/ d A/d A/d A/ d
A A A A A A A A A A A A A A A
N N N N N N N N N N N N N N N
B. This question is concerned w i t h th e w a y in w h i c h instruments get into the dentist's hands during different operating procedures. Dentists vary considerably in the extent to which they obtain the instruments themselves or have them passed by a dental assistant this regard w e are interested in ho w y o u think the handling of instruments is carried In out during different procedures. For each alternative D D/a E A/d A 16 17 18 19 20
item listed, indicate w h o h a n d l e s the instruments oy circling the one that best applies : Usually obtained b y dentist More often obtained b y d entist than p assed b y assistant Equally by dentist and assistant More often pas s e d b y a s sistant than obtained b y dentist U sually passed b y assistant
Instruments during surgery Hand instru ments for cavity pre p a r a t i o n Handpiece during cavity preparation Amalgam pluggers Amalgam carriers
D D D D D
D/ a D/a D/a D/a D/a
E E E E E
A/d A/ d A/ d A/ d A/ d
A A A A A
N N N N N
Fig. I • C h airsid e task inventory
general practice. These were (1) cavity preparation, (2) cavity restoration, (3) oral surgery and (4) oral prosthetics. The tasks then were grouped according to the area into which they fitted. Finally, ratings based on the probabil ity of each task’s being assigned to an assistant by a dentist were obtained. This information then was compiled and sub sequently used as a guide in the ultimate selection of the tasks included in the in ventory. The 20 tasks finally selected appear in Figure 1. The tasks cover the four areas of chairside procedures already men
tioned. The last five tasks differ from the first 15 in that they are more especially concerned with the extent to which in struments are passed to the dentist by his assistant during the treatment of pa tients. Six answer categories are provided for each task: D (usually only the dentist), D / a (more often the dentist than the assistant), E (usually either the dentist or the assistant), A / d (more often the assistant than the dentist), A (usually only the assistant), and N (usually some one other than the dentist or the assist ant) . The last response is included for
96 • J . A M E R . DENT. A S S N .: Vol. 70, Ja n . 1965
Ta b le 1 • T h ree independ ent judgments on rank o rd e r o f chairside use of six d e n ta l assistants by inventory responses and observation
Judge Dental assistant
Dentist
Assistant
Public health dentist
A B G D E F
1 2 3 4 5 6
1.5 1.5 5.0 3.0 4.0 6.0
2.5 1.0 5.5 2.5 5.5 4.0
W
(coefficient of concordance) = 0.785. Significant a t the I per cent level.
dentists whose practices do not cover all four areas of service. Since these categories are arranged ac cording to the degree of chairside use of the assistant, numerical values (or weights) from 1 to 5 were assigned to them in the order from D to A . N was given the value of zero. The particular numerical values need not, of course, be assigned as described here. The weights are open to the researcher’s choice, since different analyses may require different weighting to facilitate interpretation. The only requirement is that the numbers be in the appropriate increasing or decreas ing order. By adding the weights of the responses to each task item, a score on general assistant use could be computed for each respondent or group of respond ents. T E S T IN G V A L ID IT Y A N D R E L IA B IL IT Y O F IN V E N T O R Y
Once designed, the inventory was sub jected to a test of its validity, that is, a test to determine whether the checklist is capable of indicating the general divi sion of labor between dentists and assist ants. The test involved comparing the dentists’ and assistants’ responses to the inventory with the judgment of a dentist who acted as observer. First, the inven tory was administered separately to six dentists and to their assistants. These dentists were general practitioners lo
cated in a large metropolitan area. Pre cautions were taken against the possibility that a given dentist and his assistant might confer with each other in making the responses. The observer was a Public Health Service dentist (Samuel Wycoff) who made single, day-long observations in each dentist’s office. The final scores for each participant in the test group then were compared and ranked. The rank ings derived for the dentists and their assistants were computed from their re sponses to the chairside task inventory. The rank order given by the Public Health Service dentist was based on the per cent of observed time the assistant was used for a variety of tasks at the chairside ( Table 1). By comparing the rank orders obtained from the checklist with that from the ob servations of the observer, it was pos sible to determine the extent to which the inventory is able to secure bona fide, valid estimates of the actual use of den tal assistants. A useful device that can compare the rankings given by three or more judges is the “ W” score, also called the coefficient of concordance.2 A score of 1.0 indicates perfect agreement among the judges and a score of zero, complete disagreement. A further statistical test of this score is afforded by a “ test of sig nificance,” which simply tells what the probability is of obtaining a particular score by chance. Despite the small num
Lefcowitz and others: C H A IR S ID E TASK IN V EN T O R Y • 97
ber of tests, the “ W” score of 0.785 is high enough so that the probability is less than one in a hundred that this level of agreement could have happened by chance. Reliability of the inventory, the ques tion of whether or not it is a stable meas uring device, has not been directly ascertained yet. Nevertheless, the high coefficient of concordance suggests that it is highly reliable. Another opportunity to evaluate the chairside task inventory was provided by a study of the graduates of a particular school of dentistry who had been exposed to a course of training in the use of chairside assistants in comparison with uninstructed graduates of the same school and of other dental schools. Un der the direction of Norman Miller of the University of North Carolina, the inventory was administered to 175 den tists and their assistants.® Thus, it was possible to determine the amount of agreement— or consensus— to be found between a large number of dentists and their assistants regarding the perform ance of the 20 tasks. Figure 2 shows the frequency of paired dentist-assistant mean scores on the chairside task inven tory (C T I ). The outlined area encloses those den tists and assistants whose respective mean scores differed by less than a weight of 1. For example, in the enclosed area there were 19 dentists who had mean scores between 2.0 and 2.4, whereas their assist ants scored from 2.5 to 2.9. As can be seen, the majority of the teams, 136 of the 175, fell within this zone of con sensus. Nevertheless, a more precise statistical measure of agreement was needed in or der to provide a dependable basis for establishing the validity and reliability of the individual inventory items. Because available statistical formulas were not satisfactory in measuring agreement, a special formula was developed for mak ing such comparisons.4 The usual measures of correlation were rejected because none, to the authors’
OtHT1STS 1 .0-1 1*
1.5 - 1.9
2 .0-2 .U 2 5 -2.9
1
2
3 0-3 ii
'*•5-5 0
a
1
I
1
2.0-2.1*
a
6
17
19
7
2.5-2.9
1
1
l6
au
ao
3 .0 -3 .!*
2
5
10
3 5-3-9
2
2
1
> 5-1 9
3-5-3-9
2
1
au
7
2
2
ao
2
It 0-1* .u
a
2
1*.5-5-0
Fig. 2 • C T I mean scores of dentists com pared with those of their assistants (N = 175; C = 0.816)
knowledge, is directly addressed to the problem of determining to what extent given dentists agree or disagree with their assistants concerning the allocation of chairside tasks. Therefore, the for mula was developed to provide a direct answer to the question. This formula yields what we call a “ coefficient of congruence,” and is rend ered as: JV
6 i C =
^(xt - r,)2 =
1
1 ---------------------------------------JV(r2 -
1)
where N is the number of dentist-assistant pairs, Y t is a particular dentist’s aver age score (or the numerical value of the response to a given task item, if indi vidual tasks are being analyzed), is his assistant’s score, and r is the number of response categories. It is important to note that the use of this formula is valid only when all the weights are integers (including zero) and differ from their neighbors by no more than unity. The range of values which C (con gruence score) can take depends only on the number of response categories ( r ) . The maximum is always +1-0, whereas
98 • J . A M E R . DENT. A S S N .: Vol. 70, Ja n . 1965
T a b le 2 • C o efficien ts o f co n g ru en ce for s e p a ra te tasks. N com putations, depending on usable responses
Task no. 1 2 3 4 5
C 0.432 ' 0.816 0.844 0.448 0.300
varies from 134 to
168 fo r different
Task no.
C
Task no.
C
Task no.
C
6 7 8 9 10
0.180 0.000 0.672 0.660 0.960
11 12 13 14 15
0.352 0.348 0.596 0.056 0.188
16 17 18 19 20
0.264 0.056 0.456 0.436 0.740
the minimum is always 1 — & ( - — - V V + l/ For the Chairside Task Inventory, if the category, N , is omitted as irrelevant, C ranges from + 1 to —3.0. Positive scores indicate agreement, whereas nega tive scores indicate disagreement. Zero indicates that there is neither agreement nor disagreement. For Figure 2, note that C is equal to 0.816, which indicates an extremely high level of agreement be tween dentists and assistants. It may be of interest to note that the congruence score for the six dentist-assistant pairs who were involved in our test of validity was 0.961. The coefficient of congruence also was computed for each of the 20 tasks sepa rately. The results are shown in Table 2 (the task numbers correspond to the items listed in Figure 1). For most of the tasks, the scores were moderate to ex tremely high; however, there were sev eral tasks for which the scores were low. For example, the score for task no. 7
(selects instruments for given operation) was zero. This would seem to indicate that either the description of the task or the situation surrounding the task is am biguous. Such discoveries have prompted proposals for a rewording of several of the task descriptions. In general, we ex pect that the inventory will be subjected to periodic revision in the hope of im proving both its validity and its relia bility. T H E IN V E N T O R Y A S S E L F - A S S E S S M E N T
Although it was originally developed to evaluate specific training programs and to assess the general allocation of certain chairside tasks in dental operatories, the inventory can also be a means by which every practitioner can rate himself in the use of assistants at the chairside. The means for doing so are provided with this article. The interested dentist will find the “ rules of the game” in Figure 3. By testing his chairside “ teamsmanship,” each dentist can gain a good idea of his
WHAT IS YOUR CHAIRSIDE TEAMSMANSHIP? Fig. 3 • Rating of chairside team m anager
Interested in how you rate as a chairside team manager? Answer the questions in Figure 1, and then compute your chairside score as follows: D is worth I point. D/a is worth 2 points, E is worth 3, A/d is worth 4 and A is worth 5. Ignore those tasks for which you would check N. Add up your points' and divide by the number of items you have checked. If vou score:
Your assitant is a :
1.0 2.0 3.0 4.0
bench warmer pinch hitter utility fielder first-stringer
-
1.9 2.9 3.9 5.0
Lefcowitz and others: C H A I R SID E TASK IN V EN T O R Y - 99
T a b le 3 • C hairside teamsmanship o f 215 m etropolitan dentists a cco rding to a g e and assistant utilization
Assistants Dentist
Bench warmers (%)
Pinch hitters
Utility fielders
(%)
{%)
Less than 40 years old
30
36
29
4
40 to 49 years old
24
51
23
J
50 years and older
43
37
20
0
All ages
31
42
25
2
team performance in his office. The interested dentist can compare his performance with that of his own peers by consulting Table 3. This table gives inventory results, broken down according to age, for dentists who participated in a study conducted in a large metropolitan area by researchers at Columbia Univer sity.5 It is admitted that a breakdown on CTI results according to year of gradua tion from dental school would probably yield a more significant basis for com parison than do the age specifications found in Table 3. Unfortunately, there was no provision in the study for secur ing data specifically on year of gradua tion. Nevertheless, we think that the in formation presented in the table is not without some merit. The more curious practitioner is in vited to have his assistant take the test. Some dentists may be surprised at how different the chairside picture looks from the assistant’s viewpoint, although in most circumstances the two scores should tally closely. Whatever the situation, with both scores available, a dentist can better assess the division of labor in his own operatory. SUMMARY
The construction of an inventory to as sess chairside use of a dental assistant has been described. Data which indicated the reliability and validity of this instru
Firststringers
Total
(%) 99 (N = 96) 99 (N = 70) 100 (N = 49) 100 (N = 215)
ment also is presented. It was pointed out that the inventory could be useful to the private general practitioner in assessing the extent to which he uses his assistant for chairside tasks. Although presented in a light-hearted vein, the purpose of suggesting the use of the inventory as a self-measuring in strument was serious. Given the impor tance of chairside assistance to modem dental practices, the inventory can pro vide a means, imperfect though it may be, by which the individual dentist can obtain a periodic reading on the organi zation of his office with respect to the four-handed team approach. The authors are Indebted to Robert Bonds, Jam es Kelly, W a lte r J . Pelton, Quentin Smith, Lawrence Van Kirk and Samuel W ycoff for their help a t the vari ous stages in the developm ent of the inventory. *Chief, Social Studies Branch, Division of Dental Public Health and Resources, Public H ealth Service, US Department of Health, Education, and W elfare . fSocial science analyst, Social Studies Branch, Division of Dental Public Health and Resources, Public Health Service, US Department of Health, Education, and W elfare. 1. Turk, Herman. Social cohesion through variant values: Evidence from m edical role relations. Am . Sociol. Rev. 28:28 Feb. 1963. 2. Siegel, Sidney. Nonparam etric statistics. New York, M cGraw -Hill Book Co., Inc., 1956, p. 229-238. 3. Miller, Norman. Final report: survey of dental practices, University of North Carolina School of Den tistry. Unpublished report to the Division of Dental Public Health and Resources, US Public Health Service, I960. 4. Lefcowitz, M. J., Irelan, L. M., and Signorile, V. Indexing the division of labor In a working dyad. Paper presented a t the annual institute of the District of Columbia Sociological Society, M ay I I, 1963. 5. Columbia University School of Public Health and Adm inistrative Medicine. Exploratory survey among den tists on facilitators and barriers to the utilization of "ch airsid e " dental assistants. Report to the Division of Dental Public Health and Resources, US Public Health Service, Department of Health, Education, and W elfare 1961 (unpublished).
Myron J. Lefcowitz,* M A , Lola M. Irelan,f P h D , and Vito Signorile,! M A , W a s h in g t o n , D C
To
m e a s u r e th e e x t e n t to w h ic h d e n t a l
a s s is ta n ts w e r e b e in g u s e d a t th e c h a ir s id e , a c h e c k lis t o f 2 0 s e le c te d tas ks w a s d e v e lo p e d . T h e c h a ir s id e ta s k in v e n t o r y p r e s e n te d o ffe r s th e i n d i v i d u a l d e n tis t a c h a n c e to assess th e d iv is io n o f la b o r in h is o w n o p e r a t o r y a n d to e v a lu a t e h i m s e lf as a m a n a g e r o f th e d e n tis t-a s s is ta n t c h a ir s id e t e a m . T h e
i n v e n t o r y c h e c k lis t
a n d s c o r in g r u le s a r e p r o v id e d .
from both dental students, or practition ers, and their assistants concerning the division of 20 chairside tasks. The checklist, however, may be of value to the individual practitioner as a means of measuring the general division of labor in his own operatory. It also may be of some use to those interested in studying the extent to which various categories of dentists and their assistants function as a chairside team. D E V E L O P M E N T O F IN V E N T O R Y
In many dental schools, experimental training programs were developed to introduce students to the use of assistants at the chairside, that is, to the fourhanded team approach. Such programs were begun in response to the need for increasing the capacity of dentists to reach more people more effectively. In evaluating these programs, the Social Studies Branch of the Division of Dental Public Health and Resources, US Public Health Service was confronted with the problem of measuring the extent to which assistants were being used at the chairside. To deal with this problem, a checklist of selected chairside tasks was developed. This checklist, or “inventory,” of chairside tasks could be self-administered. It was designed to elicit responses
The general form of the inventory was suggested by the work of Turk,1 who de veloped a similar means for measuring differences in ideas about job division between student physicians and student nurses. In consultation with several den tists in the United States Public Health Service, the development of the inventory was carried through several stages. First, a list of tasks that might be performed by either the dentist or his assistant was drawn up. Then, since the main interest was in the chairside use of assistants, ob viously irrelevant tasks were discarded. Concerning the remaining tasks, it was determined that four areas would ade quately represent the typical range of chairside services offered by a dentist in
lefcow itz and others: C H A IR S ID E TASK IN V EN T O R Y • 95
Each of the items listed b e l o w refers t o an activity which is part of a dental procedure. A. For each activity, that best applies: D D/a E A/d A N 1 2 3 4 5 6 -7 8 9 10 11 12 13 14 15
-
indicate w h o perforins the activity by circling the one alternative
Usually only the dentist More often the dentist than the assistant Usually either the dentist or th e assistant More often the assistant th a n t h e dentist Usually only the assistant Usually someone other than the dentist or the assistant
Clip sutures during surgery Cement facings and p ontics in place Prepare amalgam filling material Place matrix b a n d in retainer Retract the cheek during surgery Keep field clear during c arving of restoration Select instruments for given operation Mix cement for bases Hold impression tray in p o sition after initial set Place amalgam in cavity Keep field clear during p lacing of fillings Block impression trays Change burs and stones for cavity preparations Prepare initial impression materials for prosthetics Keep field clear during cavity preparation
D D D D D D D D D D D D D D D
D/a D/a D/a D/a D/a D/a D/a D/a D/a D/a D/a D/a D/a D/a D/a
E E E E E E E B E E E E E E E
A/ d A/ d A/ d A/ d A/ d A/ d A/d A/d A/d A/d A/d A/ d A/d A/d A/ d
A A A A A A A A A A A A A A A
N N N N N N N N N N N N N N N
B. This question is concerned w i t h th e w a y in w h i c h instruments get into the dentist's hands during different operating procedures. Dentists vary considerably in the extent to which they obtain the instruments themselves or have them passed by a dental assistant this regard w e are interested in ho w y o u think the handling of instruments is carried In out during different procedures. For each alternative D D/a E A/d A 16 17 18 19 20
item listed, indicate w h o h a n d l e s the instruments oy circling the one that best applies : Usually obtained b y dentist More often obtained b y d entist than p assed b y assistant Equally by dentist and assistant More often pas s e d b y a s sistant than obtained b y dentist U sually passed b y assistant
Instruments during surgery Hand instru ments for cavity pre p a r a t i o n Handpiece during cavity preparation Amalgam pluggers Amalgam carriers
D D D D D
D/ a D/a D/a D/a D/a
E E E E E
A/d A/ d A/ d A/ d A/ d
A A A A A
N N N N N
Fig. I • C h airsid e task inventory
general practice. These were (1) cavity preparation, (2) cavity restoration, (3) oral surgery and (4) oral prosthetics. The tasks then were grouped according to the area into which they fitted. Finally, ratings based on the probabil ity of each task’s being assigned to an assistant by a dentist were obtained. This information then was compiled and sub sequently used as a guide in the ultimate selection of the tasks included in the in ventory. The 20 tasks finally selected appear in Figure 1. The tasks cover the four areas of chairside procedures already men
tioned. The last five tasks differ from the first 15 in that they are more especially concerned with the extent to which in struments are passed to the dentist by his assistant during the treatment of pa tients. Six answer categories are provided for each task: D (usually only the dentist), D / a (more often the dentist than the assistant), E (usually either the dentist or the assistant), A / d (more often the assistant than the dentist), A (usually only the assistant), and N (usually some one other than the dentist or the assist ant) . The last response is included for
96 • J . A M E R . DENT. A S S N .: Vol. 70, Ja n . 1965
Ta b le 1 • T h ree independ ent judgments on rank o rd e r o f chairside use of six d e n ta l assistants by inventory responses and observation
Judge Dental assistant
Dentist
Assistant
Public health dentist
A B G D E F
1 2 3 4 5 6
1.5 1.5 5.0 3.0 4.0 6.0
2.5 1.0 5.5 2.5 5.5 4.0
W
(coefficient of concordance) = 0.785. Significant a t the I per cent level.
dentists whose practices do not cover all four areas of service. Since these categories are arranged ac cording to the degree of chairside use of the assistant, numerical values (or weights) from 1 to 5 were assigned to them in the order from D to A . N was given the value of zero. The particular numerical values need not, of course, be assigned as described here. The weights are open to the researcher’s choice, since different analyses may require different weighting to facilitate interpretation. The only requirement is that the numbers be in the appropriate increasing or decreas ing order. By adding the weights of the responses to each task item, a score on general assistant use could be computed for each respondent or group of respond ents. T E S T IN G V A L ID IT Y A N D R E L IA B IL IT Y O F IN V E N T O R Y
Once designed, the inventory was sub jected to a test of its validity, that is, a test to determine whether the checklist is capable of indicating the general divi sion of labor between dentists and assist ants. The test involved comparing the dentists’ and assistants’ responses to the inventory with the judgment of a dentist who acted as observer. First, the inven tory was administered separately to six dentists and to their assistants. These dentists were general practitioners lo
cated in a large metropolitan area. Pre cautions were taken against the possibility that a given dentist and his assistant might confer with each other in making the responses. The observer was a Public Health Service dentist (Samuel Wycoff) who made single, day-long observations in each dentist’s office. The final scores for each participant in the test group then were compared and ranked. The rank ings derived for the dentists and their assistants were computed from their re sponses to the chairside task inventory. The rank order given by the Public Health Service dentist was based on the per cent of observed time the assistant was used for a variety of tasks at the chairside ( Table 1). By comparing the rank orders obtained from the checklist with that from the ob servations of the observer, it was pos sible to determine the extent to which the inventory is able to secure bona fide, valid estimates of the actual use of den tal assistants. A useful device that can compare the rankings given by three or more judges is the “ W” score, also called the coefficient of concordance.2 A score of 1.0 indicates perfect agreement among the judges and a score of zero, complete disagreement. A further statistical test of this score is afforded by a “ test of sig nificance,” which simply tells what the probability is of obtaining a particular score by chance. Despite the small num
Lefcowitz and others: C H A IR S ID E TASK IN V EN T O R Y • 97
ber of tests, the “ W” score of 0.785 is high enough so that the probability is less than one in a hundred that this level of agreement could have happened by chance. Reliability of the inventory, the ques tion of whether or not it is a stable meas uring device, has not been directly ascertained yet. Nevertheless, the high coefficient of concordance suggests that it is highly reliable. Another opportunity to evaluate the chairside task inventory was provided by a study of the graduates of a particular school of dentistry who had been exposed to a course of training in the use of chairside assistants in comparison with uninstructed graduates of the same school and of other dental schools. Un der the direction of Norman Miller of the University of North Carolina, the inventory was administered to 175 den tists and their assistants.® Thus, it was possible to determine the amount of agreement— or consensus— to be found between a large number of dentists and their assistants regarding the perform ance of the 20 tasks. Figure 2 shows the frequency of paired dentist-assistant mean scores on the chairside task inven tory (C T I ). The outlined area encloses those den tists and assistants whose respective mean scores differed by less than a weight of 1. For example, in the enclosed area there were 19 dentists who had mean scores between 2.0 and 2.4, whereas their assist ants scored from 2.5 to 2.9. As can be seen, the majority of the teams, 136 of the 175, fell within this zone of con sensus. Nevertheless, a more precise statistical measure of agreement was needed in or der to provide a dependable basis for establishing the validity and reliability of the individual inventory items. Because available statistical formulas were not satisfactory in measuring agreement, a special formula was developed for mak ing such comparisons.4 The usual measures of correlation were rejected because none, to the authors’
OtHT1STS 1 .0-1 1*
1.5 - 1.9
2 .0-2 .U 2 5 -2.9
1
2
3 0-3 ii
'*•5-5 0
a
1
I
1
2.0-2.1*
a
6
17
19
7
2.5-2.9
1
1
l6
au
ao
3 .0 -3 .!*
2
5
10
3 5-3-9
2
2
1
> 5-1 9
3-5-3-9
2
1
au
7
2
2
ao
2
It 0-1* .u
a
2
1*.5-5-0
Fig. 2 • C T I mean scores of dentists com pared with those of their assistants (N = 175; C = 0.816)
knowledge, is directly addressed to the problem of determining to what extent given dentists agree or disagree with their assistants concerning the allocation of chairside tasks. Therefore, the for mula was developed to provide a direct answer to the question. This formula yields what we call a “ coefficient of congruence,” and is rend ered as: JV
6 i C =
^(xt - r,)2 =
1
1 ---------------------------------------JV(r2 -
1)
where N is the number of dentist-assistant pairs, Y t is a particular dentist’s aver age score (or the numerical value of the response to a given task item, if indi vidual tasks are being analyzed), is his assistant’s score, and r is the number of response categories. It is important to note that the use of this formula is valid only when all the weights are integers (including zero) and differ from their neighbors by no more than unity. The range of values which C (con gruence score) can take depends only on the number of response categories ( r ) . The maximum is always +1-0, whereas
98 • J . A M E R . DENT. A S S N .: Vol. 70, Ja n . 1965
T a b le 2 • C o efficien ts o f co n g ru en ce for s e p a ra te tasks. N com putations, depending on usable responses
Task no. 1 2 3 4 5
C 0.432 ' 0.816 0.844 0.448 0.300
varies from 134 to
168 fo r different
Task no.
C
Task no.
C
Task no.
C
6 7 8 9 10
0.180 0.000 0.672 0.660 0.960
11 12 13 14 15
0.352 0.348 0.596 0.056 0.188
16 17 18 19 20
0.264 0.056 0.456 0.436 0.740
the minimum is always 1 — & ( - — - V V + l/ For the Chairside Task Inventory, if the category, N , is omitted as irrelevant, C ranges from + 1 to —3.0. Positive scores indicate agreement, whereas nega tive scores indicate disagreement. Zero indicates that there is neither agreement nor disagreement. For Figure 2, note that C is equal to 0.816, which indicates an extremely high level of agreement be tween dentists and assistants. It may be of interest to note that the congruence score for the six dentist-assistant pairs who were involved in our test of validity was 0.961. The coefficient of congruence also was computed for each of the 20 tasks sepa rately. The results are shown in Table 2 (the task numbers correspond to the items listed in Figure 1). For most of the tasks, the scores were moderate to ex tremely high; however, there were sev eral tasks for which the scores were low. For example, the score for task no. 7
(selects instruments for given operation) was zero. This would seem to indicate that either the description of the task or the situation surrounding the task is am biguous. Such discoveries have prompted proposals for a rewording of several of the task descriptions. In general, we ex pect that the inventory will be subjected to periodic revision in the hope of im proving both its validity and its relia bility. T H E IN V E N T O R Y A S S E L F - A S S E S S M E N T
Although it was originally developed to evaluate specific training programs and to assess the general allocation of certain chairside tasks in dental operatories, the inventory can also be a means by which every practitioner can rate himself in the use of assistants at the chairside. The means for doing so are provided with this article. The interested dentist will find the “ rules of the game” in Figure 3. By testing his chairside “ teamsmanship,” each dentist can gain a good idea of his
WHAT IS YOUR CHAIRSIDE TEAMSMANSHIP? Fig. 3 • Rating of chairside team m anager
Interested in how you rate as a chairside team manager? Answer the questions in Figure 1, and then compute your chairside score as follows: D is worth I point. D/a is worth 2 points, E is worth 3, A/d is worth 4 and A is worth 5. Ignore those tasks for which you would check N. Add up your points' and divide by the number of items you have checked. If vou score:
Your assitant is a :
1.0 2.0 3.0 4.0
bench warmer pinch hitter utility fielder first-stringer
-
1.9 2.9 3.9 5.0
Lefcowitz and others: C H A I R SID E TASK IN V EN T O R Y - 99
T a b le 3 • C hairside teamsmanship o f 215 m etropolitan dentists a cco rding to a g e and assistant utilization
Assistants Dentist
Bench warmers (%)
Pinch hitters
Utility fielders
(%)
{%)
Less than 40 years old
30
36
29
4
40 to 49 years old
24
51
23
J
50 years and older
43
37
20
0
All ages
31
42
25
2
team performance in his office. The interested dentist can compare his performance with that of his own peers by consulting Table 3. This table gives inventory results, broken down according to age, for dentists who participated in a study conducted in a large metropolitan area by researchers at Columbia Univer sity.5 It is admitted that a breakdown on CTI results according to year of gradua tion from dental school would probably yield a more significant basis for com parison than do the age specifications found in Table 3. Unfortunately, there was no provision in the study for secur ing data specifically on year of gradua tion. Nevertheless, we think that the in formation presented in the table is not without some merit. The more curious practitioner is in vited to have his assistant take the test. Some dentists may be surprised at how different the chairside picture looks from the assistant’s viewpoint, although in most circumstances the two scores should tally closely. Whatever the situation, with both scores available, a dentist can better assess the division of labor in his own operatory. SUMMARY
The construction of an inventory to as sess chairside use of a dental assistant has been described. Data which indicated the reliability and validity of this instru
Firststringers
Total
(%) 99 (N = 96) 99 (N = 70) 100 (N = 49) 100 (N = 215)
ment also is presented. It was pointed out that the inventory could be useful to the private general practitioner in assessing the extent to which he uses his assistant for chairside tasks. Although presented in a light-hearted vein, the purpose of suggesting the use of the inventory as a self-measuring in strument was serious. Given the impor tance of chairside assistance to modem dental practices, the inventory can pro vide a means, imperfect though it may be, by which the individual dentist can obtain a periodic reading on the organi zation of his office with respect to the four-handed team approach. The authors are Indebted to Robert Bonds, Jam es Kelly, W a lte r J . Pelton, Quentin Smith, Lawrence Van Kirk and Samuel W ycoff for their help a t the vari ous stages in the developm ent of the inventory. *Chief, Social Studies Branch, Division of Dental Public Health and Resources, Public H ealth Service, US Department of Health, Education, and W elfare . fSocial science analyst, Social Studies Branch, Division of Dental Public Health and Resources, Public Health Service, US Department of Health, Education, and W elfare. 1. Turk, Herman. Social cohesion through variant values: Evidence from m edical role relations. Am . Sociol. Rev. 28:28 Feb. 1963. 2. Siegel, Sidney. Nonparam etric statistics. New York, M cGraw -Hill Book Co., Inc., 1956, p. 229-238. 3. Miller, Norman. Final report: survey of dental practices, University of North Carolina School of Den tistry. Unpublished report to the Division of Dental Public Health and Resources, US Public Health Service, I960. 4. Lefcowitz, M. J., Irelan, L. M., and Signorile, V. Indexing the division of labor In a working dyad. Paper presented a t the annual institute of the District of Columbia Sociological Society, M ay I I, 1963. 5. Columbia University School of Public Health and Adm inistrative Medicine. Exploratory survey among den tists on facilitators and barriers to the utilization of "ch airsid e " dental assistants. Report to the Division of Dental Public Health and Resources, US Public Health Service, Department of Health, Education, and W elfare 1961 (unpublished).