The data were collected from 280 patients. The mean age was 42.3 ± 14.7 years. The majority of the patients (61.8%) were scheduled for surgeries in governmental hospitals. Of the patients, 152 (54.3%) were female, 142 (50.7%) were less than 42 years old, 73 (26.1%) were single, 83 (29.6%) had a university education, 138 (49.3%) were currently employed, and 166 (59.3%) lived in urban areas. The majority of the patients reported moderate satisfaction with their household income, social life, and religious commitment. Of the patients, 175 (62.5%) had chronic diseases, 206 (73.6%) were scheduled to be operated on within 24 h, 239 (85.4%) were scheduled to receive general or regional anesthesia, 194 (69.3%) have had previous surgeries, 27 (9.6%) have had surgical complications, and 84 (30.0%) were scheduled to receive general surgery. The detailed demographic, clinical, and surgical variables of the patients are shown in Table 1.

Table 1 Detailed demographic, clinical, and surgical variables of the patients (n = 280)APAIS scores

The mean APAIS total score was 13.6 ± 5.9, the mean APAIS anxiety domain score was 8.3 ± 4.3, and the mean APAIS need for information domain was 1.6 ± 0.50. Of the patients, 76 (27.1%) had high anxiety and 160 (57.1%) expressed a high need for information. The detailed responses of the patients are shown in Table 2.

Table 2 Detailed responses of the patients on the APAIS itemsAssociation between APAIS scores with demographic, clinical, and surgical variables of the patients

The t tests, ANOVA, chi-square, and Fisher’s exact tests showed that APAIS total and APAIS anxiety scores were significantly higher for the patients who were female, younger than 42 years, married, employed, had chronic diseases, scheduled to be operated on within 24 h, scheduled to receive general or regional anesthesia, had experienced surgical complications, and were scheduled to receive either obstetrical/gynecological, ophthalmological, general, or ear, nose, and throat operation. On the other hand, the APAIS need for information scores were significantly higher for patients who were female, scheduled to be operated on within 24 h, scheduled to receive general or regional anesthesia, whose surgery would be performed in a governmental hospital, and who were scheduled to receive ophthalmological operation. Differences in APAIS scores are shown in Supplementary Table S1 and associations between demographic, clinical, and surgical variables of the patients with anxiety and need for information categories are shown in Supplementary Table S2.

To control potentially confounding factors, the variables that were significantly associated in the t tests and ANOVA were included in multiple linear regression models. The models showed that higher APAIS total scores were predicted by being female, scheduled to be operated on within 24 h, and having experienced surgical complications. The higher APAIS anxiety scores were predicted by being female, having chronic diseases, being scheduled to be operated on within 24 h, and having experienced surgical complications. On the other hand, higher APAIS need for information scores were predicted by being scheduled to be operated on within 24 h and operated in a governmental hospital. Details of the multiple linear regression are shown in Table 3.

Table 3 Details of the multiple linear regression with APAIS scores

To control potentially confounding factors, the variables that were significantly associated in the Chi-square or Fisher’s exact tests were included in multivariate logistic regression models. Female patients were 2.89 times (95% CI 1.44–5.81) more likely to express high anxiety compared to male patients. On the other hand, patients to be operated within 24 h, scheduled to receive general or regional anesthesia, and those to be operated in governmental hospitals were 2.04-times (95% CI 1.15–3.60), 2.36-times (95% CI 1.14–4.88), and 2.08-times (1.24–3.50) compared to those who would be operated after 24 h, scheduled to receive local anesthesia, and those to be operated in private hospitals. Details of the multivariate logistic regression models are shown in Table 4.

Table 4 Details of the multivariate logistic regression models with APAIS categoriesSTAIS-5/STAIT-5 scores

The mean STAIS-5 score was 10.0 ± 4.2 and the mean STAIT-5 was 10.3 ± 3.8. Of the patients, 140 (50.0%) had high state anxiety and 56 (20.0%) had high trait anxiety. The detailed responses of the patients are shown in Table 5.

Table 5 Detailed responses of the patients on the STAIS-5/STAIT-5 itemsAssociation between STAIS-5 and STAIT-5 scores with demographic, clinical, and surgical variables of the patients

The t tests, ANOVA, chi-square, and Fisher’s exact tests showed that STAIS-5 scores were significantly higher for patients who were female, younger than 42 years, married, employed, scheduled to be operated on within 24 h, and scheduled to receive either obstetrical/gynecological, ophthalmological, general, or ear, nose, and throat operations. On the other hand, the STAIT-5 scores were significantly higher for patients who were female, scheduled to receive general or regional anesthesia, and scheduled to receive either obstetrical/gynecological, cardiac surgery/interventions, ophthalmological, general, or ear, nose, and throat operations. Differences in STAIS-5 and STAIT-5 scores are shown in Supplementary Table S3 and associations between demographic, clinical, and surgical variables of the patients with anxiety and need for information categories are shown in Supplementary Table S4.

To control potentially confounding factors, the variables that were significantly associated in the t-tests and ANOVA were included in multiple linear regression models. The models showed that higher STAIS-5 scores were predicted by being female, younger than 42 years, and scheduled to be operated on within 24 h. On the other hand, higher STAIT-5 scores were predicted by being female. Details of the multiple linear regression are shown in Table 6.

Table 6 Details of the multiple linear regression with STAIS-5 and STAIT-5 scores

To control potentially confounding factors, the variables that were significantly associated in the Chi-square or Fisher’s exact tests were included in multivariate logistic regression models. Patients who were female, younger than 42 years, and married were 2.61-times (95% CI 1.53–4.46), 1.90-times (95% CI 1.14–3.15), and 2.02-times (95% CI 1.11–3.66) more likely to express high state anxiety compared male, 42 years and older, and single patients, respectively. On the other hand, the patients who were female and those who were younger than 42 years were 1.99-times (95% CI 1.06–3.71) and 1.95-times (95% CI 1.06–3.60) more likely to express high trait anxiety compared to male and 42 years and older patients, respectively. Details of the multivariate logistic regression models are shown in Table 7.

Table 7 Details of the multivariate logistic regression models with STAIS-5 and STAIT-5 categoriesCorrelation between APAIS total, APAIS anxiety, APAIS need for information, STAIS-5, and STAIT-5 scores

There was a strong and positive correlation between APAIS total scores with APAIS anxiety scores (Pearson’s r = 0.90, p value < 0.001), and APAIS need for information scores (Pearson’s r = 0.74, p value < 0.001). On the other hand, there was a moderate and positive correlation between APAIS total scores and STAIS-5 scores (Pearson’s r = 0.60, p value < 0.001) and STAIT-5 scores (Pearson’s r = 0.41, p value < 0.001). There was a moderate correlation between APAIS anxiety scores and APAIS need for information scores (Pearson’s r = 0.39, p value < 0.001), STAIS-5 scores (Pearson’s r = 0.65, p value < 0.001) and STAIT-5 scores (Pearson’s r = 0.40, p value < 0.001). Similarly, there was a weak and positive correlation between APAIS need for information scores and STAIS-5 scores (Pearson’s r = 0.28, p value < 0.001) and STAIT-5 scores (Pearson’s r = 0.27, p value < 0.001). Moreover, there was a moderate and positive correlation between STAIS-5 scores and STAIT-5 scores (Pearson’s r = 0.46, p value < 0.001).