A total of 767 responses were received. Thirty-nine were excluded as they were from radiologists, nuclear medicine physicians, or radiation oncologists. Thus, 728 pertaining to only referring physicians were used for further analysis. Responses originated from 28 countries. In total, 381 (52.3%) responses were from developed countries and the remaining 347 (47.7%) from developing countries. exemplifies the relative magnitude of the two groups of physicians. The distribution of responses under the developed countries category and the number of responses (in parentheses) is: Australia (1), Cyprus (3), Czech Republic (268), Finland (90), Ireland (1), Slovenia (4), Spain (1), the UK (1), the USA (12). Accordingly, for 347responses from developing countries, Armenia (2), Bulgaria (1), Brazil (26), China, Peoples Republic of (5), Croatia (37), Macedonia, Former Yugoslav Republic of (41), Georgia (2), Hungary (14), India (50), Indonesia (24), Iran (16), Kazakhstan (15), Lebanon (12), Lithuania (2), Malaysia (14), Moldova, Republic of (4), Pakistan (43), Philippines (21) and Sri Lanka (18). Of 728 respondents, 339 (46.6%) were residents, 370 (50.8%) were consultants and 19 (2.6%) did not provide data about level of expertise. An overview of all the answers for each question is given in .
Graphic representation of the relative size of the groups of survey participants originating from developing and developing countries.
Importance of acquiring information about previous diagnostic exposures of patients
presents results against each theme of the questionnaire. Responses to question A.1 showed that physicians rarely ask patients about previous radiological examinations (never 8.5% and occasionally 48.1% against very often 28.1% and always 15.3%). In question A.2, nearly two-thirds (67.7%) preferred to choose the purpose of asking about previous radiological examinations as ‘both’ radiation risk, and clinical need or radiation risk only. In question A.3, the vast majority of physicians (84.3%) state that their decision would be affected if they knew that a patient has undergone 10 or more CT scans in the last 2 years. The situation is similar for question A.7 where 67.2% stated that they would find it difficult to prescribe a next CT scan to a patient who has already received a dose of about 100 mSv. The answers to question A.4 also concurred with the idea that patients who have received higher doses are harder to be referred for a next examination. In question A.5, ‘How frequently do you come across situations where the clinical indications are enough to prescribe a CT scan irrespective of the previous history of CT scans?’, the choice ‘rarely’ was opted by a very small number of respondents (19.0%), and an almost equal number of responses were for ‘very frequently’ (40.1%) and ‘occasionally’ (40.9%). Two-thirds (65.7%) considered patient age to be an important factor in their decision-making for referring patients for CT investigations (A.9).
Position of respondents regarding the themes tested in this study
The vast majority of physicians (71.7%) stated that knowing the history of previous CT scans would always, or mostly, help them in making a better decision (A.6). This concurs with their opinion expressed against question A.8, that a system providing them with quick information about patient exposure history will be helpful (60.5%). Only 7.7% responded ‘not really’ in question A.8, thus indicating strong support for utility of tracking. depicts the percentages for all answers in question A.8.
Overall answers of participants regarding their opinion on whether having a system by which they would have quick information about patient-exposure history would be helpful (question A.8.).
For theme A, overall 65.1% of physicians had a positive position regarding the importance of acquiring information about previous patient exposures (). This study did not find any statistically significant differences among physicians in different categories.
Statistical analysis results for the different themes and groups of physicians studied in this work
Knowledge about radiation units and age-related radiosensitivity
Only one-third (34.7%) of respondents chose the correct option of the number of chest X-rays with equivalence of an abdominal CT scan. Over half (58.6%) of the physicians underestimated the abdominal CT scan dose (in terms of chest X-ray equivalent). Only a small percentage (13.6% and 12.6%) provided the correct answer of 50 and 100 X-ray equivalence, respectively (B.2). shows how random the received answers were. Overall, 47.4% of participants overestimated the dose from abdominal and pelvic X-rays. In question B.3, the vast majority (>90%) of respondents answered correctly on which imaging modality imparts the highest radiation dose. Surprisingly, 2.2% of respondents chose a totally incorrect answer (MRI), with another 5% choosing another incorrect answer of skull X-ray. In open question B.4 on ‘What is your assessment of radiation dose in mSv for one chest CT scan?’, overall, 56.6% answered ‘dose is between 5 and 20 mSv’ which was considered to be the correct range. Almost 75% of physicians stated that they find radiation units confusing (35.9% confusing and 38.2% somewhat confusing). For the open question B.6, ‘How do you solve the confusion of radiation units in your practice?’ the answers received were found to belong in one of the following categories: I seek consultation, I seek education, I do some research, I find no solution/I do not know. A large number of physicians (298) did not answer and 30.7% of those who answered responded that they do not solve the problem at all.
Overall answers of participants regarding their estimation of equivalent number of chest X-rays for (abdomen+pelvic) X-ray (question B.2.).
A satisfying 92.4% of participants answered correctly to question B.7, concerning the most radiosensitive patient group. In question B.8, regarding the least radiosensitive group of patients, 56.4% of participants answered correctly. A considerable percentage of 40.6% erroneously answered that the least radiosensitive group is adult patients.
and show that significantly more consultants (69.2%) than residents (59.0%) provided more correct than wrong answers in the questions of theme B and, thus, they appeared to be more knowledgeable about radiation doses and age-related radiosensitivity (p=0.0048). Similarly, physicians coming from developed countries were significantly more knowledgeable than those from developing countries (p=0.0304).
Opinions on whether patients should be provided information about their radiation dose and risks
The majority of physicians (71.7%) stated that they very rarely or never come across patients who discuss the radiation dose issue with them. In total, 70.9% stated that they do not feel uncomfortable when patients ask about radiation risk from CT scans they prescribe. In question C.3, 80.1% of participants stated that information about radiation dose in CT should be provided to patients in the report of the examination or that they would not bother if patients were provided with that information. In question C.4, 27.4% of physicians stated that mandatory written justification of CT scans would be very helpful in achieving better radiation protection, while another 47.9% appeared to have no problem with that, thus totalling to 75.3%.
Significantly more physicians from developed countries were found to be positive regarding the notion of theme C in favour of providing patients with information about dose prior to their radiation exposure (p=0.0238). Overall, 80.8% were positive regarding theme C, in favour of providing information to patients.
Physicians’ self-assessment of appropriateness of referral
The majority of physicians answered that they have rarely prescribed a CT scan which they subsequently realised was of no clinical use. Only 8.7% of consultants think that on retrospective hindsight they often or very often ordered a CT scan of no clinical usefulness. Significantly more residents provided similar answers in comparison with senior consultants (16.3%, p=0.0027).