Growth patterns in a cohort of very low birth weight infants in Johannesburg: a retrospective review

Thesis MMed (Paediatrics), Faculty of Health Sciences, University of the WitwatersrandINTRODUCTION: Improved survival of VLBW infants is raising several management issues. An example is that of growth and growth monitoring. AIM OF THE STUDY: To assess the growth of a cohort of VLBW infants born at CMJAH from term CGA to 20 months CGA. METHODS: A retrospective chart review was conducted on 139 VLBW infants (birth weight ≤ 1500g) born at CMJAH between 1 July 2006 and 28 February 2007. RESULTS: Comparison with a term growth reference showed initial growth failure followed by gradual catch up growth but with persistent deficits in length for age. Comparison with international VLBW references showed similar growth for weight and head circumference for age but with deficits in length for age. Growth parameters of the study sample were similar to those of other South African VLBW infants. CONCLUSION: Growth and growth monitoring in VLBW infants is complicated by characteristic growth patterns, high associated morbidity, controversies surrounding ideal growth and lack of an ideal growth reference. Significant deficits in length for age in the study sample may have been due to the large proportion of infants born SGA and the high prevalence of stunting in South African children. Current recommendations for growth monitoring of VLBW infants include the use of a VLBW reference up to two years CGA followed by a term growth reference thereafte

Patient and community nurse perspectives on recruitment to a randomized controlled trial of urinary catheter washout solutions

Aims To provide evidence around the acceptability of a proposed randomised controlled trial (RCT) of catheter washout solutions. Design: A sample of senior community nursing staff (n=7) were interviewed and four focus groups with a sample of community nurses were conducted. Eleven semi-structured face-to-face interviews were undertaken with patients using a long-term catheter. Methods: An in-depth qualitative study using a phenomenological approach was employed. This approach was suitable to explore the lived experiences of subjects and gain their viewpoints and experiences. Results: Nurse participants raised concerns regarding the removal of treatment or increased risk of infection in relation to which arm of the trial patients were randomised to. There was concern that patients could get used to the increased contact with nursing staff. Six patients who agreed to participate cited personal benefit, benefiting others, and a sense of indifference. Four patients were unsure about taking part and one declined

Fee Structure and Surrender Incentives in Variable Annuities

Variable annuities (VAs) are investment products similar to mutual funds, but they also protect policyholders against poor market performance and other risks. They have become very popular in the past twenty years, and the guarantees they offer have grown increasingly complex. Variable annuities, also called segregated funds in Canada, can represent a challenge for insurers in terms of pricing, hedging and risk management. Simple financial guarantees expose the insurer to a variety of risks, ranging from poor market performance to changes in mortality rates and unexpected lapses. Most guarantees included in VA contracts are financed by a fixed fee, paid regularly as a fixed percentage of the value of the VA account. This fee structure is not ideal from a risk management perspective since the resulting amount paid out of the fund increases as most guarantees lose their value. In fact, when the account value increases, most financial guarantees fall out of the money, while the fixed percentage fee rate causes the fee amount to grow. The fixed fee rate can also become an incentive to surrender the variable annuity contract, since the policyholder pays more when the value of the guarantee is low. This incentive deserves our attention because unexpected surrenders have been shown to be an important component of the risk faced by insurers that sell variable annuities (see Kling, Ruez and Russ (2014) ). For this reason, it is important that the surrender behaviour be taken into account when developing a risk management strategy for variable annuity contracts. However, this behaviour can be hard to model. In this thesis, we analyse the surrender incentive caused by the fixed percentage fee rate and explore different fee structures that reduce the incentive to optimally surrender variable annuity contracts. We introduce a "state-dependent" fee, paid only when the VA account value is below a certain threshold. Integral representations are presented for the price of different guarantees under the state-dependent fee structure, and partial differential equations are solved numerically to analyse the resulting impact on the surrender incentive. From a theoretical point of view, we study certain conditions that eliminate the incentive to surrender the VA contract optimally. We show that the fee structure can be modified to design contracts whose optimal hedging strategy is simpler and robust to different surrender behaviours. The last part of this thesis analyzes a different problem. Group self-annuitization schemes are similar to life annuities, but part, or all, of the investment and longevity risk is borne by the annuitant through periodic adjustments to annuity payments. While they may decrease the price of the annuity, these adjustments increase the volatility of the payment patterns, making the product risky for the annuitant. In the last chapter of this thesis, we analyse optimal investment strategies in the presence of group self-annuitization schemes. We show that the optimal strategies obtained by maximizing the utility of the retiree's consumption may not be optimal when they are analysed using different metrics

Serum 1,3-βD-Glucan assay in the diagnosis of invasive fungal disease in neonates

Invasive fungal disease is a significant cause of morbidity and mortality in the neonate. The current study aims to assess the 1, 3-βD-Glucan (BG) assay in a prospective analysis in neonates with suspected fungaemia. A multicentre, prospective cohort study was conducted in Johannesburg, South Africa. The study included 72 neonates with clinically suspected late onset sepsis who were at high risk of fungaemia. A BG assay was performed on each patient and correlated with a sepsis classification based on the full blood count, C-reactive protein and blood culture results as no fungaemia, possible fungaemia, probable fungaemia or definite fungaemia. Sensitivity and specificity of the BG assay at levels of 60 pg/mL are 73.2% and 71.0% respectively and at levels of 80 pg/mL are 70.7% and 77.4% respectively. Positive and negative predictive values at 60 pg/mL are 76.9% and 66.7% respectively and at 80 pg/mL are 80.6% and 66.7% respectively. The area under the receiver operating curve is 0.753. The BG assay is a useful adjunct to the diagnosis of invasive fungal disease in neonates. It does, however, need to be considered in the context of the clinical picture and supplementary laboratory investigations