Prevalence and Factors Associated With Loss to Follow-up Among Thyroid Disease Patients at Kenyatta National Hospital Paediatric Endocrinology Clinic Between January 2013 to December 2022

Abstract

Background: Thyroid diseases are among the most common endocrine conditions worldwide with 33.3% of cases occurring in children aged 1-3 years. Hypothyroidism is the most prevalent thyroid disease (30.6%) of cases followed by hyperthyroidism at 11.6%. Thyroid masses are rare in children. Most patients diagnosed with thyroid disease need long-term follow-up to achieve complete remission. There is however, high rate of loss of follow-up (LTFU) ranging between 24 – 47% which translates to approximately one half of all patients on treatment. The transition of medical care from pediatric to adult life requires close monitoring to achieve good patient outcomes and improve patient’s quality of life. Despite high risk of LTFU among children with thyroid disease, there is limited data on prevalence and reasons associated with LTFU among patients in our setting. The objectives of this study were to determine the prevalence of LTFU as well as associated factors among patients with thyroid disease on follow-up at Kenyatta National Hospital (KNH) pediatric endocrinology clinic between January 2013 to December 2022. Methods: This was a retrospective cross-sectional study based on hospital records that included all pediatric patients with thyroid disease on follow up at KNH pediatric endocrinology clinic between January 2013 to December 2022. All children and adolescents who had been enrolled to the clinic and diagnosed with thyroid disease before the age of 18 years, with complete biodata and documented clinician diagnosis with supporting laboratory results were enrolled into the study. Consecutive sampling technique was used to recruit patients. Files of two hundred eligible children and adolescents were retrieved and 5 were excluded as they had visited the clinic only once for expert opinion. Relevant data was abstracted using a pretested structured questionnaire. Telephone interviews were conducted to obtain data from patients lost to follow-up who were identified through contact tracing.

Loss to follow up was defined as a failure to attend 2 consecutive clinic appointments or at the time of first visit was send for laboratory investigations and never came back and upon contact tracing, patient was not on follow up by an endocrinologist or was unreachable through the phone. For descriptive analysis, study variables were grouped into categorical and continuous variables. Categorical variables were presented using frequencies (n) and percentages (%) while continuous variables were presented using means (SD) and Medians (IQR). Univariate and multivariate analysis was done using binary logistic regression. Results: Out of 195 children with thyroid disease enrolled in the study, 101(51.8%) were male and 131(67.2%) had been diagnosed with thyroid disease during infancy. Hypothyroidism was documented in 85.1% of the patients. Prevalence of LTFU (LFTU) was 43.1% (95% Confidence Interval (CI): 36.3% -50.1%). Most of the LTFU, (47.6%), occurred within one to three years post-diagnosis and coincided with the covid 19 pandemic. The mean time for LTFU based on each person contribution and probability was 59.8(95% CI 53.0-66.7) months. Major reasons for LFTU included: financial constraints (54%), caregivers moved out of Nairobi (11.9%) and 10.7% alleged that child became well. On Multivariable analysis male gender, was associated with LTFU, Adjusted Odds Ratio (AOR)= 2.61, (95%CI: 1.19 – 3.93), while on Univariate analysis, prematurity was protective, AOR 0.39, (95% C1 0.11-1.41). A third of the patients had died while 9.2% could not be reached. Patients with hypothyroidism had the highest mortality at 33.7% over the 10-year follow up period. Conclusion and recommendations: The burden of LTFU among children diagnosed with thyroid disease was high. Major reasons given for LTFU included: financial constraints, caregivers moved out of Nairobi, patient followed up in the nearest facility when need arises and child became well. Male gender was associated with LFTU while prematurity was

protective. There was high mortality among children with hypothyroidism. Study results highlight the need to foster collaboration between health care workers and community leaders to address the multifaceted challenges faced by families.