1. Background
2. Objectives
3. Methods
3.1. Sample Size Calculation
3.2. Questionnaire Development
| Knowledge Item | Correct Answer (%) | Item-Total Correlation (r_pb) | Discrimination Level |
|---|---|---|---|
| CT scanning increases lifetime cancer risk | 88.7 | 0.54 | Good |
| Children are more sensitive to radiation than adults | 91.9 | 0.62 | Very good |
| MRI and USG do not involve ionizing radiation. | 85.6 | 0.51 | Good |
| Weight is an important parameter affecting radiation dose | 81.5 | 0.49 | Good |
| CT has the highest average radiation dose. | 88.0 | 0.57 | Very good |
| An abdominal CT in a child is equivalent to approximately 300 chest X-rays. | 29.3 | 0.26 | Moderate |
| ALARA (as low as reasonably achievable) | 41.5 | 0.33 | Moderate |
| ALARA compliance includes low dose, shielding, avoiding unnecessary exams, and using alternatives. | 37.8 | 0.31 | Moderate |
| Overall; mean ± SD/cronbach α | 71.9 ± 15.2 | α = 0.87 | - |
Abbreviations: r_pb, point-biserial correlation coefficient; ALARA, as low as reasonably achievable; CT, computed tomography; MRI, magnetic resonance imaging; USG, ultrasonography.
a Values are expressed as the percentage of participants providing a correct response.
b The dose-equivalence figure for abdominal CT (approximately 300 chest X-rays) is based on published estimates (9); actual values may vary with patient size, scanner protocol, and imaging parameters.
3.3. Ethical Assessment
3.4. Statistical Analysis
4. Result
| Variables | No. (%) |
|---|---|
| Gender | |
| Female | 139 (62.6) |
| Male | 83 (37.4) |
| Specialty | |
| Pediatrics | 133 (59.9) |
| Family medicine | 89 (40.1) |
| Years of professional experience (y) | |
| 0 - 5 | 85 (38.3) |
| 6 - 10 | 67 (30.2) |
| 11 - 20 | 45 (20.3) |
| ≥ 21 | 25 (11.3) |
| Type of healthcare institution | |
| City hospital | 155 (69.8) |
| State hospital | 34 (15.3) |
| University | 18 (8.1) |
| Other healthcare facility | 15 (6.8) |
a City hospitals: Large tertiary-level Ministry of Health hospitals; State hospitals: District-level public hospitals; University hospitals: Academic medical centers affiliated with medical faculties; Other: Private hospitals and primary care centers.
| Comparison | Group 1 | Group 2 | P-Value |
|---|---|---|---|
| Specialty (pediatrics vs. family med.) | 74.1 ± 17.8 (133) | 68.3 ± 20.6 (89) | 0.038 |
| Gender (female vs. male) | 72.9 ± 19.1 (139) | 69.1 ± 20.0 (83) | 0.091 |
| Experience (0 - 5 vs. ≥ 21) (y) | 73.8 ± 20.9 (85) | 65.4 ± 18.0 (25) | 0.045 |
| Institution (university vs. other) | 77.6 ± 18.3 (18) | 69.2 ± 20.4 (204) | 0.022 |
| ALARA (yes vs. no) | 76.3 ± 17.2 (80) | 61.2 ± 20.4 (142) | < 0.001 |
| Protocol (yes vs. no) | 72.5 ± 18.1 (98) | 60.4 ± 20.9 (124) | < 0.001 |
| CT knowledge (yes vs. no) | 69.5 ± 19.2 (129) | 56.7 ± 21.6 (93) | 0.001 |
| Dose considered in decision (yes vs. no) | 68.3 ± 19.7 (153) | 59.2 ± 21.4 (69) | 0.012 |
Abbreviations: ALARA, as low as reasonably achievable; CT, computed tomography.
a Values are expressed as mean ± SD (n).
b Comparisons between two groups used the independent samples t-test or the Mann-Whitney U test, depending on normality (Shapiro-Wilk).
c Comparisons across four experience groups were performed using one-way ANOVA or the Kruskal-Wallis test.
| Variables | B | Std. Error | t-Value | P-Value | Comments |
|---|---|---|---|---|---|
| Constant | 42.17 | 3.84 | 10.98 | < 0.001 | - |
| ALARA training (present) | +5.46 | 1.12 | 4.88 | < 0.001 | Positively associated with higher knowledge score |
| Dose reduction protocol (present) | +4.82 | 1.08 | 4.46 | < 0.001 | Positively associated with higher knowledge score |
| CT dose knowledge (present) | +3.91 | 1.25 | 3.13 | 0.002 | Positively associated with higher knowledge score |
| Frequency of test requests (per level increase) | +0.31 | 0.09 | 3.52 | 0.001 | Positively associated with higher knowledge score |
| Professional experience 6 - 10 (ref: 0 - 5) (y) | -0.82 | 1.21 | -0.68 | 0.421 | Not significant |
| Professional experience 11 - 20 (ref: 0 - 5) (y) | -1.54 | 1.29 | -1.19 | 0.218 | Not significant |
| Professional experience ≥ 21 (ref: 0 - 5) (y) | -2.91 | 1.38 | -2.11 | 0.048 | Lower knowledge score relative to 0–5 years |
| Gender (female) | +2.14 | 1.02 | 2.10 | 0.037 | Positive association with knowledge score |
| Includes dose in decision (yes) | +2.77 | 1.11 | 2.49 | 0.013 | Positively associated with higher knowledge score |
| Specialty (family medicine, ref = pediatrics) | -3.76 | 1.38 | -2.72 | 0.008 | Negative association with knowledge score |
| Age | +0.09 | 0.11 | 0.79 | 0.433 | Not significant |
| Academic title (specialist/instructor/assoc. prof.) | +0.64 | 0.77 | 0.83 | 0.408 | Not significant |
| Institution type (university/city/state) | +0.52 | 0.84 | 0.62 | 0.536 | Not significant |
Abbreviations: ALARA, as low as reasonably achievable; B, unstandardized regression coefficient; SE, standard error.
a Professional experience was dummy-coded with 0 - 5 years as the reference group; three contrast rows are shown (6 - 10 y, 11 - 20 y, ≥ 21 y), each representing the mean difference in knowledge score relative to the 0 - 5 year group. All other categorical variables were similarly dummy-coded.
b B coefficients represent mean differences in knowledge score holding all other variables constant.
c 95% confidence intervals: ALARA training [3.26, 7.66]; Dose reduction protocol [2.70, 6.94]; CT dose knowledge [1.46, 6.36]; Frequency of requests [0.13, 0.49]; Experience 6 - 10 y [-3.20, 1.56]; Experience 11 - 20 y [-3.97, 0.89]; Experience ≥ 21 y [-5.62, -0.20]; Gender (female) [0.14, 4.14]; Dose in decision [0.59, 4.95]; Specialty (FM) [-6.47, -1.05].
![Distribution of knowledge score [%] Distribution of knowledge score [%]](https://brieflands.com/journals/ijp/articles/167989/figures/ijp-36-2-167989-i001-preview.webp)