Demographic characteristics and nurse-led service provision

Of the 262 invited participants, 157 questionnaires were returned; 5 were excluded as they had more than 30% missing data giving a final response rate of 58% (N = 152; 68 males and 84 females). Table 1 presents the demographic, diagnosis and treatment characteristics of respondents.

Table 1 Demographic and treatment/diagnosis characteristics of patients (N = 152)

Most respondents (n = 93, 61.2%) attended routine endocrine visits every six months. Within the two years prior to the study, 44 (28.9%) respondents had visited the Nurse-led Clinic at least four times, 35 (23%) three times, 42 (27.6%) twice, and 31 (20.4%) at least once. Length of consultation with the endocrine Advanced Nurse Practitioner (ANP) ranged from 10 to 60 min, with the majority (n = 118, 77.7%) lasting 20 to 30 min. Twenty-one respondents (13.8%) required an urgent face-to-face consultation with the endocrine ANP and were seen within three days. Additionally, 53 (34.9%) and 67 (44.1%) respondents used telephone and email, respectively, to contact the endocrine ANP, with email being the preferred communication method for 88 (57.9%) respondents, as video consultations were not available.

Construct validity and exploratory factor analysisThe satisfaction and knowledge subscale

The 18-item subscale was suitable for exploratory factor analysis (EFA), as evidenced by a determinant of 0.00041, surpassing the threshold of 0.00001 to exclude multicollinearity. The Pearson’s correlation matrix indicated no significant high correlations (r > 0.80, p < 0.001). Bartlett’s chi-square test of sphericity confirmed statistical significance (χ2 = 1455.62, p < 0.001), and the Kaiser–Meyer–Olkin (KMO) measure of sampling adequacy was 0.898, well above the minimum acceptable value of 0.50 [43]. Cronbach’s α for the subscale was 0.90.

The initial analysis identified four components with eigenvalues above 1, according to Kaiser’s criterion [44]. However, Field notes that this criterion maybe inaccurate for samples under 250 subjects with an average communality below 0.60 [43]. Given that the current study had a sample size of 152 and a mean communality of 0.54, the number of factors was determined using Cattell’s scree test [41]. The scree plot indicated a clear break after the third point, suggesting a 2-factor solution which explained 51.9% of the total variance, with 42.8% attributed to the first factor and 9.1% to the second.

Factor interpretation was facilitated by an oblique, direct oblimin rotation. Except for item 17, all items had loadings above 0.30 (Table 2) and were included in the final scale. The two factors showed moderate correlation (Pearson’s r = 0.65; p < 0.001). The domains were identified as: Factor 1: Satisfaction with Treatment and Care Service (α = 0.86), and Factor 2: Knowledge of Treatment and Condition” (α = 0.87). Although item 15 loaded similarly on both factors, it was assigned to Factor 2 based on its content. The corrected item-total correlations for the 17-item subscale exceeded 0.30 for both factors, with an overall Cronbach’s α of 0.91 (Table 2).

Table 2 Factor loadings, internal consistency and descriptive statistics for the Satisfaction and Knowledge subscale (N = 152)The adherence subscale

The 8-item subscale was suitable for EFA, showing a determinant of 0.212, KMO of 0.611 and statistically significant Bartlett’s test of sphericity (χ2 = 228.78; p < 0.001). The mean communality was 0.49, and Cattell’s scree test [41] suggested a one-factor solution accounting for 30.6% of the total variance. Since only one factor emerged, rotation was not applicable. Only five items had loadings above 0.30 and were retained in the final Adherence subscale; items 5, 7 and 8 were excluded. Post-EFA, Cronbach’s α improved to 0.69 from 0.57, and all corrected item-total correlations exceeded 0.30 (Table 3).

Table 3 Factor loadings, internal consistency and descriptive statistics for the Adherence subscale (N = 152)

The revised 22-item TASK-Q scale demonstrated high internal consistency with a Cronbach’s α of 0.90, an increase from 0.85 before EFA.

Figures 1, 2, 3 depict the percentage in frequencies of responses for the TASK-Q domains.

Fig. 1

Percentage of responses for items in the Satisfaction subscale (N = 152)

Fig. 2

Percentage of responses for items in the Knowledge subscale (N = 152)

Fig. 3

Percentage of responses for items in the Adherence to treatment scale (N = 152)

Pearson’s product-moment correlation test showed a significant positive relationship between the three factors (domains) of the TASK-Q scale, as follows:

1)

r (F1: satisfaction and F2: knowledge) = 0.67, p < 0.001;

2)

r (F1: satisfaction and F3: adherence) = 0.23, p = 0.005;

3)

r (F2: knowledge and F3: adherence) = 0.43, p < 0.001.

A one-way ANOVA analysis between the mean score of Knowledge and Adherence items [F(13, 123) = 3.66, p < 0.001] indicates that patients knowledgeable about the management of their condition were more likely to adhere to their treatment regimens and were able to recognize the benefits and necessity of their medication. Additionally, significant correlations were observed between Satisfaction items 6, 8, 9, 14 (Table 2) and the mean Adherence score [r = 0.272, r = 0.252, r = 0.332, r = 0.250; p < 0.001 respectively]. Further one-way ANOVA analysis confirmed these findings [item 6: F(3, 123) = 3.50; item 8: F(3, 123) = 2.80; item 9: F(3, 123) = 3.26; item 14: F(3, 123) = 2.41; all significant at p < 0.001], suggesting that patients who were well-informed about their medication and potential side effects, and actively involved in their treatment planning, demonstrated better treatment adherence.

Criterion-related validity: concurrent and convergent validityConcurrent validity and determinants of nonadherence

A one sample t-test analysis indicated no significant differences in satisfaction and knowledge levels between males and females; however, females reported significantly higher adherence to medication (M = 4.11, SE = 0.95) compared to males (M = 3.82, SE = 0.92) [t (150) = −2.16, p = 0.03]. Respondents diagnosed for more than 6 years reported significantly higher levels of satisfaction and knowledge (M = 3.91, SE = 0.06) compared to those diagnosed for less than 6 years (M = 3.43; SE = 0.12) [t (150) = −3.80, p < 0.001], though there were no differences in treatment adherence.

A series of crosstab analyses revealed no significant associations between the mean adherence score and individual pituitary replacement therapies, namely levothyroxine, glucocorticoids, estrogen, testosterone, growth hormone, and desmopressin. Similarly, no correlations were found between adherence and diagnosis categories as per Table 1, although the small number of respondents per category may explain this finding. Notably, patients on two or more pituitary replacement therapies reported significantly higher adherence (M = 4.13, SE = 0.07) than those on only one therapy (M = 3.56, SE = 0.14) [t (66) = −3.56, p = 0.001]. Cross-tabulation showed that 44.6% (21 of 47) of respondents taking only one medication were on daily growth hormone (GH) injections. Among the 97 respondents on daily GH injections, 24 (24.7%) reported they never or rarely took all their injections daily, 26 (26.8%) missed at least one injection per week, and 23 (23.7%) missed most injections when away from home.

A negative correlation was observed between glucocorticoid replacement therapy and adjusting medication during sick days (r = −0.415, p < 0.001); however, this improved to a positive correlation in patients diagnosed for more than 6 years (r = 0.241, p < 0.05). Cross-tabulation showed that among the 69 patients on glucocorticoid replacement, 16 (23%) rarely or never increased their hydrocortisone dose when unwell, despite 58 (91.6%) of them having been informed about how to adjust their treatment during sick days. Additionally, a lack of awareness about medication side effects correlated with nonadherence (r = −0.421, p < 0.01). Patients informed about potential symptoms of poor condition management and those able to recognize hormone imbalances reported higher treatment adherence levels (r = 0.250, p < 0.01 and r = 0.369, p < 0.01 respectively).

A negative correlation was found between the mean adherence score and the presence of health problems in addition to the endocrine condition (r = −0.205, P = 0.015), suggesting that patients with comorbidities reported impaired adherence to their treatment, likely due to the complexities of polypharmacy. Furthermore, a chi-square test revealed a significant association between the presence of comorbidities and the frequency of attending the endocrine clinic [χ2(3) = 11.171, p = 0.011, N = 152], highlighting the increased support needs of these patients. However, no associations were found between the frequency and length of consultations and the treatment satisfaction, knowledge and adherence.

Convergent validity (LSQ and free-text analysis)

Strong positive correlations, significant at the p < 0.01 level, were observed between most domains of the TASK-Q and LSQ scales using Pearson’s product-moment correlation test, supporting convergent validity (Table 4). This indicates that patients satisfied with their care tend to report higher levels of treatment satisfaction, knowledge, and adherence.

Table 4 Correlations between TASK-Q and LSQ domains (Pearson’s product moment correlation test)

Thematic content analysis of the 73 (48% of N = 152) free-text comments further validates the TASK-Q. Almost all comments endorsed the TASK-Q content domains and items. Specifically, 36 (49%) patients noted the endocrine ANP's provision of clear and understandable information, 5 (7%) appreciated the support for their family, 14 (19%) felt empowered and engaged in treatment decision-making, 15 (21%) praised the ANP’s professional competence, and 11 (15%) highlighted the empathy and personal approach of the endocrine ANP. Additionally, 19 (26%) patients emphasized the value of continuity of care in the Nurse-led Clinic and the holistic approach adopted by the endocrine ANP, who regarded patients as individuals rather than medical cases.