Israel Medical Association Journal

Background: Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder characterized by inattention, impulsivity and hyperactivity. Recently, increases in ADHD prevalence and methylphenidate use have been reported. There is evidence that children and adolescents use ADHD medication only during the school year. 

Objectives: To investigate trends in methylphenidate dispensing over a period of 3 years (2010–2012) at the monthly level and to investigate whether there is any monthly variation, especially during the summer season.

Methods: The database of Clalit Health Services (the largest of the four health funds in Israel) was used to identify (i) patients aged 6–17 years with a diagnosis of ADHD, and (ii) methylpenidate dispensation during the period 2010–2012. 

Results: Among children aged 6–17 years diagnosed with ADHD, 43% were treated with methylphenidate. For the period 2010 to 2012 there was an annual drop in methylphenidate dispensing, beginning in June and continuing through the 2 months of summer vacation, with a 2.5-fold reduction from July as compared to May. This decline was consistently followed by a rise in medications dispensed starting August. A similar small drop was observed during the Passover school vacation. The summer drop decreased over the years.

Conclusions: Our findings showed a decrease in the number of methylphenidate prescriptions dispensed during the summer months and Passover as compared to the rest of the year. However, this phenomenon appears to be decreasing. Given that ADHD is a chronic disease state that can effectively be managed with pharmacotherapy, discontinuation of treatment may be harmful for patients and should be considered only on a patient-by-patient basis.

 

Objectives: To examine the effect of seasonality, weather and holidays on hip fracture incidence in older adults. The study population comprised 2050 patients aged 65 years or more who sustained a proximal hip fracture.

Methods: The computerized files of the patients were reviewed for trends in incidence by season, precipitation, minimum and maximum temperatures, day of the week, and certain Jewish festivals.

Results: Hip fractures were more likely to occur in the winter than in the summer (P < 0.0001). Factors that significantly correlated with hip fracture were the maximum daily temperature (r = -0.746, P = 0.005) followed by the minimum daily temperature (r = -0.740, P = 0.006) and precipitation (r = 0.329, P = 0.02). There were fewer fractures on Saturdays (the Sabbath) as compared to other days of the week (P = 0.045). Researching the incidence on Jewish festivals, we found an elevated incidence on Passover (P < 0.0001) and a reduced incidence on the Day of Atonement (Yom Kippur) (P = 0.013).

Conclusions: In older people there is an elevated incidence of proximal hip fractures during the winter and on the Jewish festivals. On weekends and on the Day of Atonement the incidence of proximal hip fractures was reduced.

Background: Hypovitaminosis D has been shown to be extremely common in various regions around the world, mostly at high latitudes. Israel is characterized by certain features – cultural (e.g., ethnic isolates) and geographic (e.g., sunny climate) – that have been identified for their possible association with vitamin D status.

Objectives: To conduct an ecological study on a representative sample of the population of Israel, testing vitamin D status across age groups, genders, ethnic groups, and seasons.

Methods: We obtained serum samples from 195 healthy Israeli volunteers representing a broad demographic spectrum. Serum concentrations of 25(OH)D were measured with the commercial kit Liaison 25(OH)D Assay (DiaSorin, Italy).

Results: The mean vitamin D level for the entire cohort was surprisingly low (22.9 ± 10.1 ng/ml), with 149 subjects (78%) suffering from vitamin D insufficiency (< 30 ng/ml). Vitamin D status was better in infants than in older age groups. Differences by gender were significant only in the infant age group (i.e., vitamin D status was worse among females) and were not prominent across older ages. Israelis of Ashkenazi origin had higher vitamin D mean levels than those of Sephardic origin, who, in turn, had higher vitamin D levels than Arab subjects (31.4 ± 12, 24.1 ± 10, and 17.6 ± 9 ng/ml respectively). With regard to season, there were no differences between the samples collected in winter and the samples collected in summer.

Conclusions: The results suggest that hypovitaminosis D is common across all ages, genders and seasons in Israel, a country characterized by a sunny Mediterranean climate. Specific ethnic groups may be at especially high risk.

Objectives: To compare the seasonality of children with T1DM in different populations around the world for which data were available.

Methods: We analyzed large cohorts of T1DM patients with a clinical disease onset before age 14 or 18 years.

Results: We found a seasonality pattern only in ethnically homogenous populations (such as Ashkenazi Jews, Israeli Arabs, individuals in Sardinia and Canterbury, New Zealand, and Afro-Americans) but not in heterogeneous populations (such as in Sydney, Pittsburgh and Denver).

Conclusions: Our findings attempt to explain the controversial data in the literature by showing that ethnically heterogeneous populations with a mixture of patients with various genetic backgrounds and environmental exposures mask the different seasonality pattern of month of birth that many children with diabetes present when compared to the general population.