the utilization of health services: sequence of visits to general practitioners
TRANSCRIPT
Sot. SC;. Mrd. Vol. 16. pp. 2065 to 2072. 1982 Printed in Great Britain. All rights reserved
0277-9536/82/232065-08sO3.00/0 Copyright 0 1982 Pergamon Press Ltd
THE UTILIZATION OF HEALTH SERVICES
SEQUENCE OF VISITS TO GENERAL PRACTITIONERS
FRANCOIS BELAND
Ministire des Affaires Sociales, Service de L’Evaluation-Sank, 1005 Chemin Se Foy, Qutbec GIS 4N4, Canada
R&urn&-Les etudes multivarites de la consommation des visites midicales n’ont pas donnir de rtsultats probants. Le pourcentage de variance expliquk est souvent rest& peu impressionnant. Par contre, des
. etudes de clientkles spkialistes ont eu plus de sucds. La consommation des services des omnipraticiens pendant une certaine pkriode de temps peut se concevoir comme une stquence de visites mtdicales. Ces skquences peuvent itre identifikes et des groupes spkialisks de consommateurs dtsignts. La notion de sequence n’est pas dtfinie par celle de quantiti de vi&es habituellement employ&e dans les ttudes d’accessibilitk aux services de sank. En utilisant des donnies de la Rtgie de I’Assurance-Maladie du Quebec. le concept de stquences est illustrt et une partie des variations dans les configurations de skquences expliquies par I’ige et le sexe.
Abstract-Multivariate studies of health services ulitization have been particularly disappointing. Some of the difficulties might be within the conceptualization of the utilization concept. The purpose of this paper is to suggest that propensity to utilize should be expressed in time sequences and that an explanation should be sought for such sequences, rather than for the total number of times physicians are consulted. Using data from the universal health insurance scheme in Quebec. the concept of sequence of visits is illustrated, while variations in sequences of utilization than by age and sex.
utilization patterns are better explained by the
UTILIZATION: A UNIDIMENSIONAL
PHENOMENON?
The utilization of health services (or overutilization) is a topic which is debated almost periodically in Quebec, whose universal health plan unlike plans in several other Canadian provinces, provides access to services without any direct charges. The effects of di- rect charges on the frequency of utilization are well- known. They are inversely proportional to individual and socio-economic status in general, given equival- ent charges [l-7]. In particular, the establishment of Quebec’s health insurance plan made health services in the Montreal area more accessible to the poor [a121.
As in the United States. when Medicaid and Medi- care were introduced, the number of visits made to doctors by the more affluent decreased, while the number made by the poor increased [13-151. Leaving aside considerations on the effect of medical practice on health [16,17] and the depersonalized nature of the doctor-patient relation [ 181, government policy concerning health care utilization was guided throughout the 1970s by the concept that all citizens should be equal before the health system [19-221.
However, the utilization of health services is also affected by factors other than the amount charged directly or indirectly for such utilization. Health care utilization is a complex. largely unexplained phenom- enon and the influence of financial obstacles seems to have diminished in relation to other types of difficul- ties with the passage of time [13. 14,20,233. In gen- eral, studies of the conditions affecting access to health services have been characterized by a relative lack of success [20.21.X-29]. Nevertheless, studies
based on specific rather than nation-wide samples have produced better results, as is the case with studies including variables connected to the patient- doctor relationship [30].
The multivariate studies using large samples have been particlilarly disappointing. Mechanic [28] has suggested that the difficulties encountered by such studies arise from the way the issues are conceptua- lized, the type of indicators used, the way the data are aggregated and the analytical methods employed. Andersen [20] concludes that systematic distortion in the measurement of health service utilization is negli- gible, but occurs more regularly with respect to the poor, who underestimate their use of health services. In countries where the method of remunerative acts necessitates keeping a central file of visits to doctors, this difficulty can be resolved (see [31] for example). However, the measure of state of health used as an indicator of needs remains problematic. The multi- plicity of factors affecting the relation between the stage of health, symptoms and the decision to consult C32.333 may be considered as one of the reasons for the disappointing results of utilization models for which the state of health is given as the main reason for consulting a physician. It has therefore been pro- posed that the ‘decision to consult’ process be studied 134.353.
In large-scale multivariate studies of health services utilization, the term ‘propensity to visit a doctor’ has sometimes been used [19]. The concept of propensity implies that for each individual. or group of individ- uals, there is, at any given moment, a probability P of using health services. Btland [36], Froggat et al. [37]. Kilpatrick C29.38.40.411 have used the concept of propensity in their studies of visits to physicians
2065
2066 FRANCOIS BELAND
primary care. Rather than observe a series of socio- demographic, psychosocial and socio-medical vari- ables in a sample of individuals and then study their relation to utilization, these researchers attempted to identify the form of the observed distribution of visits with a theoretical distribution derived from a Consul- tation model. In general, random distribution of pro- pensity to consult a doctor was rejected for the target samples; the consultation model in which physicians were considered to have the most influence on the actual utilization was not supported by the data. In fact, propensity to visit a doctor appeared to be distri- buted according to group. These findings ‘seem to contradict those of the large-scale multivariate studies. If propensity to visit a physician is distributed according to group, it is difficult to explain why the twenty-nine or so characteristics identified by Wolinsky [29] account for only l-16% of the vari- ance in the use of services offered by physicians, hos- pitals or dentists. These characteristics should have made it possible to identify some of the features of the groups as well as how they differ from one another.
The variable ordinarily used to measure health ser- vices utilization is either that of the total amount of visits per period or the dichotomous variable of con- sulting or not consulting physicians. The concept of propensity to use health services may represent a more complex reality. The purpose of this paper is to suggest that propensity is expressed in time sequences of consulting or not consulting physicians and that an explanation should be sought for such sequences, rather than for the total number of times doctors were consulted or not.
A reviewer has suggested that the concept of sequence is not distinct from the concept of the amount of health services used over a certain period of time. The\concept of sequence implies that the ser- vices, regardless of their quantity, were used during a definite period of time. This concept also implies that sequences represent stable utilization patterns.
Sequences, do not occur as deterministic patterns of visits to physicians. They are dominated by a stochas- tic process in the sense that they define propensity to visit physicians in the future. For example, if an indi- vidual does not consult a doctor during a period X, it may be predicted that there is a probability, P1 that he will consult one in the next period, whereas for an individual who does not consult a doctor over a period X + 1, the probability Pz of his consulting a doctor in the followifig period will be less than P,.
This does not preclude the possibility that a very large number of visits might be made in either case. although, if this occurred. the new pattern might also be subject to a stochastic process. While this study deals on a modest scale with the plausibility of the concept of visit sequences, the fact that such sequences exist empirically makes it possible to ima- gine dynamic approach to utilization; with this approach, the factors determining why individuals become members of one sequence type rather than another and the way such changes affect the prob- ability that an individual will consult a doctor would become fundamental topics of research leading to an adequate empirical description of health services util- ization.
In the present study, the concept of sequences will be illustrated and its capacity for distinguishing groups of individuals with similar utilization patterns will be examined; it will be proposed that the expla- nation of propensity to visit a doctor should be sought in the characteristics which distinguish one group with a certain propensity from others with dif- ferent propensities.
AN ILLUSTRATION OF THE CONCEPT OF VISIT SEQUENCES
The concept of sequence implies that a series of events takes place in time. When different sequences are observed, it follows that the events take place dif- ferently for certain individuals. An explanation of these differences is sought in order to organize the data in a more comprehensible and more easily mani- pulated way, if the need arises.
Table 1 provides an illustration of a sequence of visits to General Practitioners made by a group of men 65 years old and over, from the island of Mon- trtal. These collated data represent visits during six periods of 2 months each in 1977. This group of men consulted a General Practitioner at least once during each of the first two periods of the year. Their sub- sequent visits were observed in the remaining periods. In the third period, about 28.6% of them did not return to a General Practitioner; by the sixth peiiod, this percentage reached 41.9%. Is there an equivalent reduction in visits for women 65 years old and over’? For all age groups? FOT all social classes? Regardless of the use previously made of health services?
The same questions which arose in studies of the total amount of health services used also arise in re-
Table 1. Example of a distribution sequence of visits to General Practitioners. Group of men, 65 or over, who made visits in the first two periods
Number of visits Utilization period
1977-l 1977-2 1977-3 1977-4 1977-5 1977-6
None - - 118 169 162 173 1 256 239 153 152 143 129 2 110 119 92 65 69 77 3 29 37 29 16 28 20 4 9 8 14 5 8 5 5 8 7 I 2 1 5 6 1 0 2 1 1 2
7 or more 0 3 4 3 1 1
The utilization of health services 2067
lation to sequences of visits to doctors. It is proposed utilization periods of each sequence in order that the here that conceptualizing utilization as sequences in relation between different propensities to visit a doc- time is more appropriate than viewing the phenom- tor and the factors of age, sex and sequence may be enon as the total amount of utilization during a established. period. The question of which approach is preferable can only be settled by the capacity of empirical studies to explain sequences.
UTILIZATION SEQUENCES
The utilization sequences observed cover 60.18% of
THE DATA USED the visits to G.P.s made on the island of Mon- treal in 1977. The 5% sample of the RAMQ file taken
The existence of sequences of visits to doctors will , bv the MAS amounts to 67.508 visits. while the be examined briefly with respect to the sex and age of beneficiaries of Quebec’s health insurance plan. A sample of 5% of the beneficiaries of the Regie d’Assur- ante-Maladie du Quebec (RAMQ) is taken on behalf of the Minis&e des Affaires Sociales of Quebec (MAS). In the present study, only beneficiaries on the island of Montreal will be observed to ensure a cer- tain uniformity in the subjects’ residential status and in the type of health care distribution system that they use.
The distributions of visits were identified for men and women of four age groups (l-l_4 years, 15-34 years, 35-64 years and 65 years and over). The year 1977 was divided into six periods of 2 months each. The utilization periods observed were established empirically to illustrate the diversity of the popula- tion’s contacts with the primary health care distribu- tion system. A distinction was drawn between those who made considerable use of primary health care services and those who used them episodically. This distinction is purely empirical: its only justification is that it illustrates the differences observed and sheds light on the way in which beneficiaries of the RAMQ on the island of Montreal consult General Prac- titioners.
Four types of sequence will be established and studied (Tables 3 and 4). The first type includes people who consulted a doctor in each of the first two periods; the distribution of their visits in the following four periods is then studied. In the second group,
visits to a doctor began in the second period, rather than in the first; the distribution of visits in the sub- sequent periods for this group is also studied. The third and fourth sequences are based on people who were not registered in the RAMQ files during the second and third periods respectively; the distribution of their subsequent utilization is also studied. Conse- quently, the first sequence corresponds to the series of visits to a General Practitioner made by people who consulted at least once in each of the first two periods; these people are important consumers. The second sequence includes those who did not consult a physician for at least 2 months; the third, those who did not consult a physician for at least 4 months; and the last sequence, those who did not visit a physician for at least 6 months.
followed by analyses of variance for the first and last
To begin with. three statistics will be used to sum- marize the distribution of visits in each of the periods for each group observed: (1) the mean number of visits: (2) the variance. to measure the dispersion of the distribution: and (3) the proportion of individuals who did not consult a physician during a given period. to measure the number of people who do not return to the primary health care system. This will be
..~ ~~ ~~ 1
The variances tend to become smaller from one sequence to the next and from one period to the next for men belonging to the first or second sequence. However, the mean number of visits shows a general tendency to decrease while the proportion of people no longer using primary care services tends to in- crease, throughout the sequences and periods. The mean number of visits in the first utilization period of the first and fourth sequences decreases from a mar- gin ranging from 1.56 to 1.66 to a margin ranging from 1.26 to 1.37 for men. For women, the equivalent means are between 1.55 and 1.91 and between 1.21 and I.35 respectively. In the last period observed, the mean number of visits for men ranges from 0.57 to 0.93 for the first sequence and from 0.24 to 0.40 for the fourth period. Between 44.8 and 67.1% of the men in the first seauence are no longer consulting General
sequences in Tables 3 and 4 account for 40,623 visits. The proportion of men and women in each sequence varies appreciably. In general, males between 1 and 14 years of age are overrepresented in each sequence; since it is usually the mothers of this age group who decides to consult, the group includes members who did not decide to consult a physician. However, the proportion of males between 1 and 14 years visiting a doctor in relation to the number of males in this age group in the total population of the island of Mon- treal is approximately the same as that for females in the same age group..This equivalence disappears in the other age groups and its absence is especially noti- ceable in the 15-34 age group. The disparity in this age group cannot be attributed solely to the effects of obstetrical care, since in the majority of cases on the island of Montreal such care is provided by specialists (Table 2).
In the first sequence, that of regular consumers, the proportion of people 65 years old and over is higher than it is for the overall population. However, their proportion in the second and third sequences ap- proximates their proportion in the overall population, while, in the sequence of least frequent utilization (sequence 4), their proportion becomes less than their proportion in the overall population. Therefore, the pattern followed by a large proportion of people 65 and over when they consult General Practitioners is equivalent to that followed by other age groups. Heavier utilization by people in this age group appears to be attributable to a relatively small sub- group of individuals; the observations made by Sha- piro and Roos [31] confirm this point.
Tables 3 and 4 present the mean number of visits, variances and the proportion of people using the primary care system in 1977. Major trends only are discussed here. The specific effects of age and sex will be dealt with in the ANOVA.
FRANCOIS BELAND
Table 2. Proportion of men and women, according to age, in each of the four utilization sequences. Island of Montreal-1977
1 st Sequence 2nd Sequence 3rd Sequence 4th Sequence
(1) (2) % % y (2) (1) (2) (1) (2) Total population*
,J % % % % % N %
Men 1-14 14.57 1.93 19.03 5.07 21.76 4.75 22.84 3.84 204.397 20.47
15-34 25.49 1.83 37.93 5.48 37.79 4.48 40.98 3.73 376,549 37.7 1 35-64 44.71 3.54 35.01 5.56 32.97 4.29 30.18 3.02 342.69 1 34.32 65 and over 15.23 5.51 8.03 5.83 7.49 4.45 6.00 2.74 75.005 7.51
Women 1-14 5.26 1.59 13.03 5.45 13.03 4.76 17.00 3.79 194,647 18.19
15-34 36.88 5.72 40.59 6.68 41.39 6.74 41.81 4.76 380.578 35.57 35-64 44.29 6.92 36.71 7.92 34.27 5.63 32.73 3.76 377,256 35.26 65 and over 13.57 6.80 9.67 6.69 9.39 4.95 8.46 3.12 117,575 10.99
(1) Proportion of group in this sequence. (2) Pronortion of zroun in this sequence for the total population. \-I -r
*Source: Super-Pip, &tbec, MAS, 1980.
Practitioners at the end of the year; the equivalent percentages for those in the fourth period are 75.2 and 82.8%. The figures are approximately the same for women, although the margin is wider in certain cases. The means range from 0.55 to 0.99 visits in the first sequence and from 0.18 to 0.30 in the fourth period. The percentage of those no longer using primary care services ranges between 41.9 and 68.7% in the first sequence and between 78.6 and 84.40/, in the fourth period.
It may be seen that the greatest decrease in the mean number of visits and the greatest increase in the proportion of people no longer using primary care services occur in the sequences corresponding to the least utilization. These increases and decreases are less extreme for people 65 years old and over. It is difficult to perceive any systematic differences related to sex in these figures.
The variances of the first sequence sets it apart from the other sequences. They are consistently higher in the first sequence than in the second; they also show less homogeneity in the first sequence than they do in the others. This homogeneity in the second, third and fourth sequences is also noticeable to some degree in their means and the proportion of people no longer using the services of General Practitioners, particularly for men. For women, the homogeneity of these figures is more pronounced in the third and fourth sequences.
The following results of the ANOVA might not be those expected. It should be remembered that this analysis makes it possible to attribute to certain factors part of the explanation of the mean number of visits to General Practitioners. Since it is impossible to constitute orthogonal contrasts with the data pro- vided by Tables 3 and 4, the analysis of variance is done using a regression model [42]. Because the total sample includes 40,623 individuals, the F-tests of sig- nificance are extremely powerful. The slightest effect of sex, age, utilization sequences or their interaction will appear significant. Wetz’s .criterion [43] is there- fore used; according to it, the level of the F-test should reach four times its value before a factor becomes important as a predictor. Similarly, the ab-
solute variations in the mean which are attributable to the factors will be studied before a conclusion is reached concerning their importance.
The analysis of variance (Table 5) for the first period provides grounds for excluding the interac- tions as a whole from the equation. The other interac- tions are rejected on the basis of Wetz’s criterion. In absolute terms, they have little effect on variations in the means for visits to doctors, since their proportion ranges from -0.0269 to 0.0579 in relation to a mean of 1.4295. It therefore seems justified to exclude the interaction of factors and to study the effect of each factor separately. Sex should be rejected as a factor, according to Wetz’s criterion. The value of the vari- ation related to this factor is only 0.0230 in an equa- tion which is restricted to the main principle effects. On the other hand, the effects of age vary linearly, with the 1-14 years age group lowering the mean and the subsequent age groups causing it to rise continu- ously. However, the most important effect is attribu- table to utilization sequences. In particular, the first utilization sequence produces an increase of 0.2888 in the overall mean, while the other sequences form an homogeneous group.
The results of the analysis of variance of the last periods are less clear, although the imeraction of all the factors remains significant at both the 0.01 level and 0.05 level of the F-test, as does the interaction between sex and sequences. The other two interac- tions are slightly above the level of Wet& criterion. The effect of the interaction between age and sequences on variations in the mean ranges from -0.0827 to 0.0609 in relation to an overall mean of 0.4341, while the interaction between age and sex has an effect ranging from 0.0475 to -0.0316. These two interactions reflect the fact that for men the youngest age group has the greatest number of visits, whereas, for women, the mean increases almost linearly in sequences 1 and 4 and decreases for the 65 years old and over age group in the other two sequences.
Although these interactions are statistically signifi- cant, their effect on the variation of the mean is rela- tively slight when it is compared to the effect of the first sequence. Since the variation due to the first
Tab
le 3
. Seq
uenc
es
of v
isits
to
Gen
era!
Pr
actit
ione
rs
in M
ontr
eal-
men
, 19
77
1977
-I
1977
-2
1977
-3
1977
-4
1977
-s
1977
-6
x s2
N
x
s2
%
iC
s2
%*
x s2
%
x
s2
%
i?
s2
%
Isi
Seq
uew
e:
peo
ple
w
ho
cis
ired
a d
octo
r in
th
efirs
t tw
o pe
riod
s I-
I4
year
s I.
66
1.48
39
5 I .
62
1.49
-
15-3
4 ye
ars
1.65
I .
40
691
1.67
I.
56
- 35
-64
year
s I .6
8 I.
29
1212
I .
72
I.38
-
65 y
ears
and
ove
r I.
56
0.80
41
3 1.
62
0.88
-
2nd
Sequ
ence
: pe
ople
w
ho
did
not
oisi
t a
doct
or
until
th
e se
cond
pe
riod
t-14
year
s 10
36
1.26
0.
44
- IS
-34
year
s 20
65
1.33
0.
54
- 35
-64
year
s 19
06
1.41
0.
68
- 65
an
d ye
ars
over
43
7 1.
36
0.41
-
3rd
Sequ
ence
: pe
ople
w
ho
did
not
visi
t a
doct
or u
ntil
the
thir
d pe
riod
l-
14
year
s 97
1 15
-34
year
s 16
96
35-6
4 ye
ars
1471
65
an
d ye
ars
over
33
4
4th
Sequ
ence
: p
eop
le
who
di
d no
t vi
sit
a do
ctor
u
nti
l th
e fo
urth
pe
riod
l-14
year
s 78
4 15
-34
year
s 14
07
35-6
4 ye
ars
1036
65
an
d ye
ars
over
20
6
*Per
cent
age
of p
eopl
e w
ho d
id n
ot v
isit
a do
ctor
du
ring
th
is p
erio
d.
0.86
I .6
9 0.
75
1.59
0.95
I .6
0 1.
28
I .66
0.34
0.
62
0.33
0.
76
0.47
0.
9 I
0.66
0.
89
1.23
0.
32
I .29
0.
57
1.42
0.
79
1.40
0.
52
53.9
0.
61
I.13
63
.3
58.3
0.
54
0.90
67
.2
47.7
0.
76
1.26
54
.0
28.6
0.
94
1.33
40
.9
77.1
0.
26
0.46
80
.6
78.4
0.
25
0.48
82
.9
70.1
0.
30
0.63
80
. I 57
.0
0.51
0.
76
66.1
- 0.
28
0.46
80
.5
0.29
0.
47
80.7
0.
27
- 0.
26
0.47
81
.9
0.22
0.
40
84.2
0.
19
- 0.
39
0.81
75
.8
0.35
0.
58
16.5
0.
29
- 0.
42
0.60
70
.1
0.47
0.
68
67.1
0.
35
I .26
0.
38
1.25
0.
35
1.35
0.
58
1.37
0.
89
- - - -
0.67
!.
I I
62.0
0.
59
I.25
61
.0
0.77
I.
19
54.0
0.
99
I.1
I 39
.2
0.31
0.
50
78.9
0.
28
0.26
0.
41
81.3
0.
23
0.38
0.
70
74.9
0.
36
0.69
I .
08
56.3
0.
51
0.26
0.
40
82.0
0.
26
0.41
81
.8
0.25
0.
43
82.9
0.
18
0.26
86
.4
0.45
I .
02
74.1
0.
30
0.58
80
.4
0.55
0.
88
66.5
0.
30
0.46
78
.6
0.59
0.
55
0.76
0.
99
I.18
65.6
I .
24
68.7
I.
12
54.1
-1
a
1.31
41
.9
E
2 N
0.53
81
.4
0.41
83
.7
$.
1 0.
69
77.2
s
1.06
67
.3
5 er
6 0.
49
82.1
x
0.32
85
.8
3.
0.47
79
.6
0 0.
47
73.4
Tab
le 4
. Se
qben
ces
of v
isits
to
gene
ral
prac
titio
ners
in
Mon
trea
l-w
omen
, 19
77
1977
-l
1977
-2
1977
-3
1977
-4
1977
-5
1977
-6
x s*
N
8
s2
%
x s2
%
x
s2
%
x s2
%
x
s2
%
1st
Sequ
ence
: pe
ople
who
vis
ited
a do
ctor
in
thej
rst
two
peri
ods.
l-
14 y
ears
1.
55
1.07
31
0 1.
47
0.91
-
0.70
1.
54
60.7
0.
48
0.73
68
.7
15-3
4 ye
ars
1.75
1.
39
2.75
1.
80
1.77
-
1.11
2.
28
48.5
0.
82
1.50
54
.1
35-6
4 ye
ars
1.91
2.
21
2612
1.
95
2.35
-
1.39
2.
85
35.8
0.
94
1.78
47
.2
65
and
year
s ov
er
1.68
1.
51
800
1.73
1.
48
- 1.
39
I .95
26
.0
1.05
1.
26
37.9
2nd
Sequ
ence
: .p
eopl
e w
ho d
id n
ot v
isit
a do
ctor
unt
il th
e se
cond
per
iod
1-l
4 ye
ars
1061
1.
25
0.37
-
0.32
0.
48
76.8
0.
22
0.32
83
.1
15-3
4 ye
ars
3304
1.
35
0.56
-
0.53
1.
06
67.9
0.
41
0.74
73
.0
35-6
4 ye
ars
2988
1.
45
0.96
-
0.68
1.
53
62. I
0.43
0.
82
73.2
65
an
d ye
ars
over
78
7 1.
38
0.66
-
0.70
1.
25
55.3
0.
46
0.62
67
.1
3rd
Sequ
ence
: pe
ople
who
di
d no
t vi
sit
a do
ctor
un
til t
he
thir
d pe
riod
I-
14 y
ears
92
7 1.
22
0.36
-
0.26
0.
33
79.7
IS
-34
year
s 25
66
1.35
0.
64
- 0.
42
0.79
73
.6
3564
ye
ars
2125
1.
43
0.80
-
0.44
0.
83
72.5
65
an
d ye
ars
over
58
2 1.
34
0.54
-
0.47
0.
82
69.2
4th
Sequ
ence
: pe
ople
w
ho
did
not
visi
t a
doct
or u
ntil
the
four
th
peri
od
I-14
yea
rs
737
1.21
0.
32
- 15
-34
year
s 18
13
1.29
0.
48
- 35
-64
year
s 14
19
1.35
0.
63
- 65
an
d ye
ars
over
36
7 1.
33
0.41
-
0.53
1.
02
67.4
0.
57
1.12
67
.1
0.83
1.
68
54.9
0.
67
1.25
61
.2
1.11
2.
14
44.3
0.
93
1.71
49
.0
1.16
1.
65
34.0
0.
93
1.33
44
.9
0.28
0.
47
80.5
0.
30
0.47
80
.1
0.47
0.
87
70.6
0.
39
0.68
74
.3
0.49
0.
93
69.4
0.
45
0.95
71
.6
0.59
0.
81
59.6
0.
42
0.62
70
.2
0.24
0.
40
82.2
0.
27
0.45
81
.2
0.43
0.
84
74.1
0.
35
0.62
76
.9
0.42
0.
78
73.3
0.
36
0.63
76
.0
0.51
0.
76
64.8
0.
38
.0.5
8 71
.7
0.26
0.
41
80.3
0.
24
0.40
82
.8
0.44
0.
86
72.8
0.
35
0.60
76
.3
0.51
1.
00
70.1
0.
40
0.80
75
.3
0.59
0.
85
64.6
0.
40
0.88
75
.2
*Per
cent
age
of p
eopl
e w
ho d
id n
ot v
isit
a do
ctor
du
ring
th
is p
erio
d.
The utilization of health services 207 I
Table 5. Analysis of variance for the first and last utilization periods
First periods Last periods Factors* F Fo.0, 4 x Fo.01 F Fo.,, 4 x Fo.o,
AxBxC 7.28 2.41 9.64 1.43 2.4 I 9.64 AxB 4.09 2.41 9.64 9.83 2.41 9.64 AxC 8.85 3.78 15.12 0.46 3.78 15.12 BxC 6.26 3.78 15.12 17.89 3.78 15.12 C 306.10 3.78 15.12 525.36 3.78 15.12 B 47.81 3.78 15.12 66.34 3.78 15.12 A 20.17 6.63 26.52 109.68 6.63 26.52
Variations in the mean due to factors in the equation: B+C A+B+c
Mean 1.4312 0.4412 Age: O-14 -0.0775 - 0.0742
15-34 0.0061 - 0.0630 35-65 0.0965 0.0468
Sequence : 1 st 0.2888 0.3228 2nd - 0.0880 - 0.0733 3rd - 0.0907 -0.1263
Sex 0.0471
*A = age; B = sex; C = sequence.
sequence is 0.3228, this factor produces a variation almost as large as the overall mean itself. The factor of sex increases the overall mean by only 0.0471.
There is a remarkable continuity in the effects from the first period to the last: (1) sex is not present in the equation for the first period and contributes a factor of about 0.05 to the overall mean in the second equa- tion; (2) with the exception of the 15-34 years age group, the total effects of age are relatively stable; and (3) the proportion of the first sequence varies only between 0.2888 and 0.3228 from the first sequence to the last, while that of the other sequences remains negative. The interactions belonging to the last period are barely significant in an ANOVA equation, accord- ing to Wetz’s criterion, despite the fact that the sample includes more than 40,000 individuals.
The effect of sex in the explanation of the mean remains weak. This result is surprising in the light of certain studies [44]. It could be foreseen in Tables 3 and 4. The question arising from this observation is answered in Table 2: women who consult doctors do so at the same rate as rrien who consult doctors, but they are more numerous.
CONCLUSION: THE EXISTENCE OF SEQUENCES
Utilisation sequences are not inflexible. In a sys- tematic manner, the mean number of visits decreases from period to period, while the number of people who cease to visit doctors increases, especially in the first sequence. which has the highest mean for visits. However, the effect of belonging to a sequence per- sists from one period to another, suggesting a certdin stability in patterns of consulting general prac- titioners.
Factors affecting the utilization of primary care ser- vices might therefore be studied with respect to sequences of visits to physicians. The identification of sequences and the conditions under which individuals change from one sequence type to another could be studied in relation to the usual socio-demographic factors and the work organization system used by the
physicians visited by such individuals. The type of protection offered by public or private health insur- ance programs, as well as the practice organizational system may either encourage the existence of certain types of sequences, or they may attract certain clients who have adopted certain sequences in the past. Clearly, the sequences studied in this paper identify regular and episodic consumers of care provided by general practitioners. The factors which explain these two patterns of visiting doctors, whether they are financial, institutional or related to states of physical, mental or functibnal health, are perhaps not continu- ous, but, rather, need to be analyzed according to utilization sequences. Similarly, financial measures to develop or restrict the medical workforce may have unequal effects on different groups of the population.
1.
2.
3.
4.
5.
6.
7
8
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