David C Southgate. Australian Optometrical Association, Carlton South, Victoria. Sixty-seven optometrists responded to a survey which sought information on a ...
Brief communication: Optometric referrals, diabetic patients and prescribing patterns. Results of a survey conducted in the period August - September 1988. David C Southgate Australian Optometrical Association, Carlton South, Victoria Sixty-seven optometrists responded to a survey which sought information on a sample of 100 patients consecutively presenting for initial consultations, providing a total sample of 6,543 patients. Eightyfive patients (1.3 per cent of the sample) were previously known to be diabetic, but presented without ocular signs of the disease. Fifty-four patients (0.83 per cent) were known to be diabetic and presented with ocular signs of the disease and 42 patients (0.64 per cent), not previously known to be diabetic, also presented with ocular signs of diabetes. It is estimated that over 11,OOO patients who were not known to be diabetic would present to Australian Optometrists annually with ocular signs of diabetes. The consultations resulted in 399 referrals to other practitioners, a referral rate of 6.1 per cent, with 58.9 per cent of these being made to ophthalmologistsand 37.3 per cent being made to general medical practitioners. Approximately one-fifth of the patients were attending an optometrist for the first time and nearly two-thirds of this group were under 30 years of age. Spectacles were prescribed for approximately two-thirdsof the patients. Key words: optometrists, diabetes, referrals, systemic disease, prescribing.
A
s primary eye care providers, Aus- made as a result of the optometric tralian optometrists frequently examination. have the first opportunity to detect eye Optometrists also regularly refer signs of systemic disease as well as patients to other health care practitionocular disease and visual disorders. ers for reasons other than diabetes, for Diabetes mellitus is a systemic con- example further management of other dition of particular interest and concern systemic conditions or ocular disease. to optometrists because of its potential Port4reported that British optometrists for serious reduction in vision. Wel- referred 6.1 per cent of their patients to born et all estimated that there were medical practitioners, and notified 250,000 known diabetics in Australia, them of disease states in another 2.5 per a prevalence of 1.6 per cent. They also cent of patients. Cockburns and Cockestimated that there were an additional burn and Gutteridge6 referred 1.8 per 75,000 to 225 ,OOO undiagnosed diabet- cent and 2.0 per cent respectively of ics. A review2 of studies of diabetic their patients to ophthalmologists in retinopathy concluded that about one- two Australian studies. Neilson’ found third of known diabetics had some form that 1.6 per cent of patients presenting of diabetic retinopathy. It also conclud- to an optometry school clinic in New ed that one-third of diabetic retinopath- South Wales were referred to another ies threatened or had already reduced practitioner. Of these, 70 per cent vision. were referred to ophthalmologists and Among optometric patients, 2.6 per 29 per cent were referred to general cent of Cockburn’s3 sample of 3798 practitioners. In 1988 the Australian Optometrical consecutively presenting patients were diabetic. Seven per cent of the diag- Association (AOA) conducted a survey noses of diabetes had initially been of optometrists, as an informal check of these results and to examine the public health role of optometrists in the detection and management of diabetic paAccepted for publication: October I I 1989. I
194
Clinical & Experimental Optometry 72.6: NvvemberlDecember I989 - 194-1 99
tients. A further objective of the survey was to assess optometrists’ patterns of referral to other practitioners. Although the above were the major objectives of the survey, the opportunity to obtain further information which could be easily collected in the process was also taken. The supplementary areas in which information was sought were in the frequency of optometric visits and in prescribing outcomes. In some ways this duplicated the work of an earlier (1977) AOA internal survey, which was directed towards many similar aspects of optometric practice, and was based on a sample of 6,075 patients.
Survey protocol Every ninth optometrist on the AOA’s member optometrist data base was mailed a survey form requesting that he or she provide details of 100 consecutively presenting initial consultations (‘Item 180’) in the period August to September 1988. One hundred and ninety-two survey forms were posted. The information requested of the optometrists for each patient was:
1. whether the patient was already known to be diabetic and whether there were any diabetic eye signs present; 2. where patients were referred to another health care practitioner, the reason for referral and the type of practitioner to whom the patient was referred; 3. age, sex and time since last optometric and medical examinations; 4. the prescribing outcome of the consultation (if any). The identities of patients were not revealed for the survey. The survey forms were returned to the AOA National Office, where staff compiled the individual responses:
Known Known Notknown diabetic, diabetic, as diabetic, no signs with signs with signs
Number AS Yo of sample
85
54
1.30
42
0.83
A summary of the results relating to diabetic patients and signs is presented
139
0.64
2.12
Total Either with diabetic signs or signs
96
181
1.47
2.77
Table 1. Diabetic patients and patients with diabetic signs.
in Table 1 . Eighty-five patients (1.30 per cent of the total sample) were previously known to be diabetic, but presented without ocular signs of the disease. There were also 54 known diabetic patients in the group (0.83 per cent) who presented with ocular signs of diabetes. Forty-two patients (0.64 per cent) who were not previously known to be diabetic presented with Results and Discussion ocular signs of diabetes, although these No effort was made to deliberately patients were not necessarily diagnosed select optometrists who would be able as being diabetic at a later stage. In total there were 181 patients (2.77 to respond to the survey. Because of the random nature of distribution, some per cent) who were either known to be optometrists, for example those work- diabetic or who presented with ocular ing part-time or in academia, received signs of diabetes. For those patients not the survey but were unable to partici- previously known as diabetics, but prepate. It is not possible to state whether senting with ocular signs of diabetes, the optometrists who responded to the the survey did not show whether these survey were representativeof the whole patients later had the diagnosis conprofession in characteristics such as age firmed. The number of all diabetics in the sample could be taken, however, as or practice location. Sixty-seven optometrists responded between 2.12 per cent (previously to the survey, a response rate of 35 per known diabetics) and 2.77 per cent cent, acceptable in the circumstances (known diabetic or with ocular signs). although far from ideal. Six optom- This result compares favourably to etrists provided information on fewer Cockburn’s3estimate of 2.6 per cent. than the requested 100 patients, which Previously known diabetics reduced the total patient sample to One hundred and thirty-nine patients 6,543 patients. In some practices where there were two or more optometrists, (2.12 per cent of the total sample, one not all of the 100 patients were exam- in 47) were previously known to be diabetic. Just over one-third of this ined by the same optometrist. In assessing the reliability of the re- group (54 patients, 39 per cent) presults, one must be mindful that the re- sented with ocular signs of diabetes. Other studies of diabetics presenting sponding practitioners did not represent a particularly large sample of the pro- in optometric practice have placed fession. However, the resultant patient greater emphasis on the incidence of sample was of a reasonable size for a diabetic retinopathy in these patients. pilot survey such as this one. The re- Cockburn3 found that the incidence of sults are felt to be sufficiently reliable diabetic retinopathy in his sample was for the AOA’s purposes of providing 26 per cent, whereas in this survey 39 information to help formulate programs per cent of the previously known diafor optometrists to best assist in the betics had ocular signs of diabetes. clinical care and monitoring of diabetic Patients with ocular signs of patients.
Diabetic patients
Total known diabetics
of this group (42 patients, 44 per cent) were not previously known to be diabetic. Of the 96 patients with diabetic signs, approximately 80 per cent had been examined by a general medical practitioner within the previous three months, 90 per cent had been examined within the previous six months and 95 per cent had been examined within the previous year.
Estimations of the number of cases to present to optometrists In 1987-88 the optometric profession provided approximately 1.8 million initial consultations to the Australian population. Combining this with the survey results provides an estimated 11,600 patients per annum with diabetic eye signs, but not previously known as diabetics, who would be examined by optometrists. In total 33,200 known diabetics (15 per cent of Welborn et af’s’ estimated 250,000) and another 26,400 patients with ocular signs of diabetes would present to Australian optometrists annually.
Total Referrals A summary of the referrals is presented
in Table 2. The optometrists referred 399 patients from their 6,543 initial consultations, an average of one referral for every 16 to 17 initial consultations (6.1 per cent). A small number of patients (fewer than 10) were referred to two practitioners. Port4found that UK optometrists referred 6.1 per cent of their patients to general medical practitioners. This figure includes, however, patients referred primarily for ophthalmological management because the UK Health Act requires that all referrals be made via general medical practitioners. Therefore the referral rate in this survey diabetes (6.1 per cent) is in keeping with Port’s4 Ninety-six patients (1.47 per cent of the findings for the United Kingdom. The total sample) presented with ocular 1977 AOA survey gave an estimated signs of diabetes. A little under half referral rate of 6.17 per cent. Clinical & Experimental Optometry 72.6:NovemberlDecember I989
195
Reason for referral*
Ophth
GP
Optom
Referred to: Chiro Neuro Educ
Paed
Surg
Total
_ .
General health Iatrogenic conditions Headaches Psychiatric
2 1 0 0
25 2 14 1
0 0 0 0
0 0 1 0
0 0 0 1
0 0 0 0
2 0 0 0
0 0 0 0
29 3
1
0
2
0
49
15
2
Group total (12.3%)
3
42
0
1
Vascular (non-specific) Diabetes Hypertension CRNCRV Arteriosclerosis
7 14 4 3 1
8 33 24 1 16
0 0 0 0 0
0 0 1 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
15 47 29 4 17
Group total (28.1%)
29
82
0
1
0
0
0
0
112
0 4 0
0 0 0
1 0 0
0 0 0
0 0 0
0 0 1
0 0 0
0 0 0
1 4 1
4
0
1
0
0
1
0
0
6
13 6 9 5 2 6
15 0 0 0 3 2
1 1 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 0 0
0 0 0 0 1 0
29 7 9 5 6 8
41
20
2
0
0
0
0
1
64
53
1
0
0
0
0
0
0
54
53
1
0
0
0
0
0
0
54
50
0
3
0
0
0
0
0
53
Group total (13.3%)
50
0
3
0
0
0
0
0
53
ARM Other macular conditions Retino-choroidal naevi Retinal dystrophies Vitreo-retinal
15 7 8 1 8
1 0 0 0 0
0 0 0 0 0
0 0
0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
16 7 8 1 8
Group total (10.0%)
39
1
0
0
0
0
0
0
40
Low acuity/amblyopia Suspicious neurological
4 7
0 2
0 1
0 0
0 1
0 0
0 0
0 0
4 11
Group total (3.8%)
11
2
1
0
1
0
0
0
15
5
1
0
0
0
0
0
0
6
5
1
0
0
0
0
0
0
6
7 1.8
2 0.5
2 0.5
1 0.3
2 0.5
1 0.3
Binocular vision Squint/paresis Learning disabilities Group total (15%) General anterior eye Keratoconus Pterygium Foreign bodies Eyelid conditions Punctum/canaliculi Group total (16.0%) Cataract Group total (13.5%) Glaucoma
Miscellaneous Group total (1 5%) Totals OO / of referrals OO / of patients
235 149 58.9 37.3 3.59 2.28
-
'See Table 3 for fuller explanations of the reasons for referral.
Table 2. Reasons for optometric referrals.
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Clinical & Experimental Opromerry 72.6: NovemberlDecember 1989
399 6.10
Types of referral
Reasons for referral
Well over half the referrals (235, or 58.9 per cent of the total 399) were to ophthalmologists. More than a third (149, 37.3 per cent) were to general practitioners and the remaining 15 referrals (3.8 per cent) were made to other optometrists, chiropractors, neurologists, an educationalist, paediatrician and a plastic surgeon. This is a distribution very similar to that found by the 1977 AOA survey, but slightly different to that found in Neilson’s7sample, where 70 per cent of referrals were to ophthalmologists and 29 per cent were to general medical practitioners. On average, one in every 28 (3.6 per cent) initial consultations resulted in referral to an ophthalmologist and one in every 44 (2.3 per cent) resulted in referral to a general practitioner. The referral rate to other optometrists is extremely low, approaching one in every loo0 consultations in this sample. Using national consultation statistics to extrapolate the survey results, Australian optometrists could be expected to make 110,OOO referrals in total each year, of which 64,600 would be referrals to ophthalmologists, 41,000 to general medical practitioners and 4,100 to other practitioners.
The reasons for referral have been grouped into similar categories, given in Table 2. Table 3 provides a fuller explanation of some of these categories. The vast majority of ‘general health’ group referrals were to general medical practitioners, while the vast majority of ‘binocular’, ‘cataract’, ‘glaucoma’, ‘low acuity’ and ‘miscellaneous’ group referrals were to ophthalmologists. One-quarter of the ‘vascular’ group and two-thirds of the ‘anterior eye’ group referrals were to ophthalmologists. Comparisons between surveys of optometrists’ referrals can be difficult because the reasons for referral are often grouped differently from survey to survey. The percentages of referrals in this survey for cataract and glaucoma ( 13.5 per cent and 13.3 per cent respectively) are close to those reported by Port4 (16.2 per cent and 15.9 per cent), Port and Pope* (14.6 per cent and 12.1 per cent), and Neilson’ (9.6 per cent and 14.7 percent). The results of Cockbum and Gutteridge6 (10 per cent and 11 per cent) are less comparable because their study was directed towards referrals to ophthalmologists only, not referrals to all practitioners. If the referral rates for cataract and
General health Psychiatric Vascular (non-specific) Diabetes Hypertension CRNCRV Arteriosclerosis Anterior eye Pyterygium Eyelid conditions Punctum/canaliculi Catara ct Glaucoma ARM Other macular conditions Retino-choroidal naevi Vitreo-retinal Low acuity/amblyopia Suspicious neurological Miscellaneous
glaucoma in this sample were maintained across the profession, Australian optometrists would refer 15,OOO patients annually for further management of cataract, and about the same number for management of glaucoma. More than 30,000 would be referred for all types of vascular disease, including diabetes.
Referrals related to diabetes In addition to the 47 referrals made specifically for the management of diabetes, there were another 15 referrals made for ‘non-specific’ signs of vascular disease, for example for retinal haemorrhages. Some, but probably not all, of these referrals would have resulted in a diagnosis of diabetes. It could therefore be stated that of the 399 referrals, between 47 and 62 ( 12 to 15 per cent) were related to diabetes. Assuming that all these ‘diabetes-related’ referrals were from the group of 277 patients known to be diabetic or with diabetic signs, 17 to 22 per cent of this group was referred for further investigation or management. Of the 47 patients who were referred specifically for management of diabetes, approximately 70 per cent had been examined by a general medical prac-
Includes a wide range of referrals for general health complaints, including allergies, epilepsy, multiple sclerosis, sinusitis,influenza,thyroid deficiency,shingles, viral infection and general debilitation. Includes referrals for anxiety. Referrals because of signs of vascular disease such a s retinal haemorrhages, where optometrist has not specified whether they relate to either diabetes or hypertension. Diabetes suspected or signs of diabetes present. Includes referrals for diabetic retinopathy. Includes referrals for suspected hypertension, transient ischemic attacks or strokes. Referrals for central retinal vein or artery occlusions, or branch occlusions. Referrals for hypercholesterolaemia and arteriosclerotic signs such as Hollenhorst plaques. Referrals for anterior eye problems including keratitis, conjunctivitis, iritis, and corneal dystrophies. Includes referrals for pingueculae. Includes referrals for blepharitis and infected secretory glands. Referrals for punctum, dacryocystitis and blocked tear ducts. Referrals for cataract and complications related to intra-ocular lenses. Includes referrals for all types of glaucoma and related to intra-ocular pressures. Age-related maculopathy (senile macular degeneration). Includes referrals for macular cysts and oedema, central serous retinopathy. Includes referrals for retinal or choroidal pigment spots, melanoma and choroiditis. Vitreous and retinal detachments, peripheral retinal degenerations and vitreous liquification. Referrals for unexplained low acuity. Referrals for suspected or detected papilloederna, unexplained visual field losses, history of head trauma, abnormal pupil reactions. Include referrals for optic disc coloboma, high ametropia and where reason for referral is unclear. Table 3. Fuller explanation of reasons for referral. Clinical & Experimental Optometry 72.6: NovemberlDecember 1989
197
titioner within the previous three months, 75 per cent had been examined within the previous six months and 90 per cent had been examined within the previous year. By extrapolation of national consultation statistics, Australian optometrists will refer 12,900 to 17,100 such patients each year. About one-third of these referrals would be made to ophthalmologists and the remainder would be made to general medical practitioners.
6-10 years
4-5years
Interval since last optometric consultation The Surveyed optometrists specifically indicated that 456 of the 6,543patients presented for an optometric examination for the first time. Some optometrists, however, did not specifically mark any of their patients as ‘first ever’ optometric patients, instead leaving the survey form blank. After adjusting the data analysis to allow for these optometrists, it was estimated that 1,190 (nearly one-fifth) of the 6,543 would have been first visit patients. The 1977 AOA survey found that 16.1per cent of patients were presenting to an optometrist for the first time. Figure 1 shows the adjusted distribution of the 6,543 patients by the time since their last ‘initial’ optometric examination. Approximately 40 per cent of the patients had not been examined by an optometrist for at least three years or had presented for their first optometric examination. By comparison, 52.7 per cent of the 1977 survey group fell within the same conditions. Figure 2 shows the age distribution of the 456 patients specifically marked as presenting for their first optometric consultation. Nearly two-thirds of these patients were aged under 30 and 75 per cent were aged under 40 years. Only five per cent were aged over 50 years.
Prescribing outcomes Spectacles were prescribed for approximately two-thirds of the patients and some.form of appliance was prescribed for over 70 per cent of the patients. There was some overlap in the prescribing outcomes, in that 0.1 per cent of patients were prescribed both single vision and multifocal spectacles, 0.9 per cent of patients were prescribed both contact lenses and spectacles and
198
1
3 years
2 years
1 year
I
1
I
PERCENTAGE OF PATIENTS (N=6448)
Figure 1. Distribution of patient sample according to time since previous ‘initial’ optometric consultation (adjusted as described in text).
70-79 60-69 n
E0
*
50-59
Q)
Y
P
40-49
3 30-39 (3
w
20-29 10-19
