This study aimed to evaluate the time interval to menarche after gonadotropin-releasing hormone agonist (GnRHa) treatment in females with central precocious puberty (CPP) and identify factors contributing to timing of menarche.Methods:We retrospectively reviewed medical records of 39 females with CPP who reached menarche after GnRHa treatment (leuprolide or histrelin). CPP diagnostic criteria were: breast development <8 years, pubertal luteinizing hormone and/or estradiol concentrations, and bone age advancement.Indications to treat are advanced bone age and psychosocial concerns. Descriptive summaries were reported as frequency and proportion for categorical variables and mean and standard deviation for continuous measures. Linear regression models were performed to evaluate the association between clinical factors with the time interval to menarche.Results:Mean age was 9.4±1.6 years at treatment onset and treatment duration was 2.2±1.4 years.Menarche occurred at 12.6±1.1 years, which was 1.04±0.5 years after treatment discontinuation. This was negatively associated with Tanner stage of breast development and bone age at treatment onset, and change in bone age during treatment. No association was seen between time interval to menarche and treatment duration, medication, or body mass index. Conclusions:We found the average time interval to menarche after GnRHa treatment in our population of female patients with CPP was 1.04±0.5 years and this is in agreement with other reports. Tanner stage of breast development and bone age at treatment onset, and change in bone age were negatively associated with time interval to menarche. This data provide clinical correlates that assist providers during anticipatory guidance of patients with CPP after GnRHa treatment.

Information is transferred through a process consisting of an information source, a transmitter, a channel, a receiver and its destination. Unfortunately, during different stages of the engineering design process, there is a risk of a design idea or solution being incorrectly interpreted due to the nonlinearity of engineering design. I.e., there are many ways to communicate a single design idea or solution. This paper provides a comprehensive review and categorization of the possible sources of information loss at different stages of the engineering design process. Next, the authors present an approach that seeks to minimize information loss during certain stages of the engineering design process. The paper i) explores design process and dissemination methods in engineering design; ii) reviews prior work pertaining to these stages of the engineering design process and iii) proposes an information entropy metric that designers can utilize in order to quantify information loss at different stages of the engineering design process. Knowledge gained from this work will aid designers in selecting a suitable dissemination solution needed to effectively achieve a design solution.

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