In our study, we have compared the Health-Related Quality of Life of hypertensive children and adolescents from patients’ and parents’ perspectives to a control sample of primary school children and their parents, using a well-validated and frequently used PedsQL™ 4.0 Generic Core Scale Questionnaire [13, 15,16,17,18, 23]. Based on our results, both hypertensive children and adolescents as well as their parents as proxy-reports report lower overall HRQoL and Psychosocial Health, together with lower Physical and Emotional Functioning scores. Additionally, the patient sample had a significantly lower School Functioning score.
Calculation of Pearson’s r revealed moderate (r > 0.5) to high (r > 0.7) positive correlations between child self- and parent proxy-reports, ranges in accordance with . This is higher than the publication on school children by Varni , with Pearson’s r values between 0.19 and 0.35, whereas some other studies have reported the correlation to be mostly in the moderate range; 0.69 in total scale scores in paediatric cancer patients  and from 0.36 to 0.64 in children with heart disease . In contrast to experience in the literature , we did not find greater child-parent agreement in observable functioning (Physical HRQoL) in comparison to non-observable functioning (Psychosocial Health). Although the observed child-parent correlations in this study were higher than expected from literature, obtaining reports from both children and parents whenever possible is still advocated because of differences in correlations between studies.
Comparing the PedsQL™ 4.0 reports of our healthy control school-based sample to reports of Slovenia’s neighbouring countries [21, 28,29,30], displayed in Table 3, our self-report sample had the highest scores in all but the Social Functioning scale. The parent proxy-reports were second-highest in all scales, with Austrian parents reporting the highest scores in five out of six scales. Although the selected primary school enrols children from different socioeconomic and ethnical backgrounds, with such high overall scores we cannot rule out a potential selection bias as well as the effect arising from a low sample size. Alternatively, the high score results may be a reflection of overall good self-reported health of Slovenian children, as reported by OECD .
On analysis of the size of mean differences between the patient and control groups, all the statistically significant differences also achieved the 5 points “cut-off” value for “minimally clinically significant difference”. Therefore, we can assume our results to be important in the clinical setting. In scores where no significant difference was observed, the mean score differences were below 5 score points.
Considering previously published literature, a meta-analysis of cross-sectional studies on HRQoL in the adult hypertensive population reported a slightly worse quality of life compared to normotensive individuals , results concordant with our own. However, in adolescents, findings from the German “KiGGS” study suggested higher self- and parent-rated quality of life, as also lower parent-rated emotional, conduct and overall problems with elevated blood pressure . The authors explained this by absence of confounding physical comorbidity and the adolescents’ unawareness of being hypertensive. The latter partially explains the discrepancy with our findings, as we only recruited patients from the clinic, who were thus mostly aware of their disease. In comparison to the study by Wong et al.  on paediatric chronic kidney disease patients, which found no significant associations between elevated blood pressure and HRQoL, a lack of hypertensive disease symptoms or more dominant chronic kidney disease symptoms might have masked the HRQoL impairments of hypertension . In our study, hypertension was the primary disease under consideration, thereby avoiding the risk of symptom misattribution. As a majority of hypertensive children report some symptoms of hypertension, including headache, insomnia, fatigue and chest or abdominal pain , impaired HRQoL seems a likely consequence.
When comparing the patient and control sample self-reports regarding to gender, no differences were found. However, in comparing age categories, we have found greatly reduced social functioning in hypertensive children compared to adolescents. While chronically ill children have been shown before to have impaired social functioning, although not diagnosis specific, age alone was not related with measures of social functioning . Even though the frequent hospital visits might play a role in this difference, further research might be needed to confirm this finding.
Certain limitations regarding our study should be addressed. First, the standardized PedsQL Questionnaire did not contain questions regarding the duration or stage of the disease, treatment modality, nor gather information on socio-economic status or other social interactions at home or in school. However, in effort to preserve cross-study comparativeness of our results, no questions were added to the questionnaire that was standardized. The enrolled hypertensive participants were, however, from the same geographical region with similar socioeconomic backgrounds, in majority diagnosed with essential hypertension. In addition, they were mostly treated with lifestyle interventions, with a negligible number of cases necessitating drug therapy. Thus, we believe our participants have been similar in major characteristics. However, future studies on these topics influencing the quality of life with a high probability are needed.
Secondly, as it was a postal survey, we could not ensure that the parents followed the written instructions posted with the questionnaires. Especially important in this aspect is the high observed child-parent concordance, which might be the result of parents influencing their child’s responses. Second, the patient and control sample differed in gender, most patients being male and controls female. Furthermore, even though obesity has been previously shown to negatively influence HRQoL [34, 35], we did not consider it a confounding factor, as it plays a major role in the development of hypertensive disease.
Finally, findings in the control population showed exceptional HRQoL in both self- and proxy-reports in relation to neighbouring countries. While we believe this to be connected to well-organized and publicly available healthcare, educational and other government systems, our findings suggest additional studies are needed to explain these unique observations. It should also be stressed that children in our country have regular preventive clinical examinations performed every 3 years including blood pressure measurements, meaning that children of control group should have been truly healthy.
The implications of our research are relevant in two aspects. First, we believe that the demonstrated study results give reason to assess the physical as well as psychosocial functioning of hypertensive children and adolescents, preferentially both from children’s as also parent’s perspectives. While the use of structured questionnaires measuring HRQoL in everyday paediatric clinical practice is under debate, according to Uzark et al. , utilizing such measures can facilitate patient-physician communication, improve patient/parent satisfaction, identify hidden morbidities, and assist in clinical decision-making. Moreover, it is advocated that specific interventions for deficits in HRQoL, including appropriate referrals, follow questionnaire findings, otherwise patient HRQoL outcomes might not be improved . An example of such HRQoL-based interventions at a cardiology outpatient practice was presented by Uzark et al. . Secondly, our findings indicate that hypertensive children differ from healthy controls in physical and psychosocial aspects. Therefore, special attention together with health-care fund allocation should be considered for this at-risk group of children, as early detection and intervention might prevent detrimental effects on psychosocial health and well-being later in life.