Browsing by Subject "Logistic Models"
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- ItemOpen AccessAnemia in type 2 diabetic patients and correlation with kidney function in a tertiary care sub-Saharan African hospital: a cross-sectional study(2016) Feteh, Vitalis F; Choukem, Simeon-Pierre; Kengne, André Pascal; Nebongo, Daniel N; Ngowe-Ngowe, MarcelinBackgroundAnemia is common in diabetic patients and increases morbidity and mortality, but its burden has been less well characterized in sub-Saharan Africans. We determined the prevalence of anemia and investigated the related factors, with a particular focus on the role of declining renal function, in type 2 diabetic patients attending a tertiary health care institution in Cameroon.MethodsHemoglobin (Hb) levels were measured in a consecutive sample of patients with type 2 diabetes, who reported for annual review at the outpatient section of the Douala General Hospital in 2013. Patients were classified as anemic according to the World Health Organisation criteria (Hb < 12g/dl for females and Hb < 13g/dl for males). Estimated glomerular filtration rate (eGFR) was calculated using the abbreviated Modification of Diet in Renal Disease Study Group formula. Determinants of Hb concentration and anemia were investigated using multivariable logistic regressions.ResultsA total of 636 patients were examined including 263 (prevalence rate 41.4%) who had anemia. The prevalence of anemia increased significantly with deteriorating kidney function, although up to 31.9% of patients with normal kidney function had anemia. Compared with their non-anemic counterparts, anemic diabetic patients were older, had longer duration of diabetes, lower eGFR, higher prevalence of proteinuria and diabetic retinopathy (all p < 0.05). In multivariable logistic regressions, eGFR (p = 0.001) and presence of retinopathy (p = 0.023) were the independent determinants of prevalent anemia.ConclusionsThe prevalence of anemia is high in type 2 diabetic patients attending referral institutions in Cameroon, including among those without chronic kidney disease. Routine screening for anemia in all diabetic patients may aid early identification and correction as appropriate.
- ItemOpen AccessAssociation between perceived built environmental attributes and physical activity among adults in South Africa(2017) Malambo, Pasmore; Pheiffer, Carmen; Lambert, Estelle V; De Villers, Anniza; Puoane, ThandiAbstract Background To investigate the association between perceived environmental attributes and leisure-time and transport-related physical activity. Methods This was a cross-sectional survey involving 671 South Africans aged ≥35 years from urban and rural settings. International Physical Activity Questionnaire and Neighbourhood Walkability Scale were used to collect data. Multivariable logistic regressions were used to investigate the associations. Results Significant urban vs. rural differences were apparent in the distribution of most attributes of neighborhood environment. After adjusting for gender, age, setting and relevant interaction terms, proximity to local stores was significantly associated with leisure-time physical activity (OR: 4.26; 95% CI, 1.00–18.08); while proximity to transit stops (2.44; 1.48–4.02), pleasant scenery (1.93; 1.07–3.46), sidewalks (2.36; 1.25–4.44), shade from trees (2.14; 1.19–3.85), traffic (2.17; 91.21–3.91) and well-lit streets (2.01; 1.04–3.89) were significantly associated with walking for leisure. Four-way intersections (4.54; 1.54–13.43), pleasant scenery (3.84; 1.35–10.99), traffic (0.28; 0.09–0.89), sidewalks (3.75; 1.06-13.27) and crosswalks were associated with transport related physical activity. Proximity to transit stops (2.12; 1.17–3.84) and well maintained sidewalks (2.69; 2.20–10.02) were significantly associated with total physical activity. Significant interactions by setting were apparent in some of the associations. Conclusion Some, but not all attributes of a neighborhood environment were significantly associated in expected directions with the three physical activity domains in this mixed urban and rural population. This study highlights the need for policy strategies aimed at improving or maintaining these perceived environmental attributes to promote physical activity.
- ItemOpen AccessChanges in self-reported HIV testing during South Africa's 2010/2011 national testing campaign: gains and shortfalls(2016) Maughan-Brown, Brendan; Lloyd, Neil; Bor, Jacob; Venkataramani, Atheendar SHIV counselling and testing is critical to HIV prevention and treatment efforts. Mass campaigns may be an effective strategy to increase HIV testing in countries with generalized HIV epidemics. We assessed the self-reported uptake of HIV testing among individuals who had never previously tested for HIV, particularly those in high-risk populations, during the period of a national, multisector testing campaign in South Africa (April 2010 and June 2011).
- ItemOpen AccessDevelopment and validation of a prognostic score during tuberculosis treatment(2017) Pefura-Yone, Eric Walter; Balkissou, Adamou Dodo; Poka-Mayap, Virginie; Fatime-Abaicho, Hadja Koté; Enono-Edende, Patrick Thierry; Kengne, André PascalBACKGROUND: Death under care is a major challenge for tuberculosis (TB) treatment programs. We derived and validated a simple score to predict mortality during tuberculosis treatment in high endemicity areas. METHODS: We used data for patients aged ≥15 years, diagnosed and treated for tuberculosis at the Yaounde Jamot Hospital between January 2012 and December 2013. Baseline characteristics associated with mortality were investigated using logistic regressions. A simple prognosis score (CABI) was constructed with regression coefficients for predictors in the final model. Internal validation used bootstrap resampling procedures. Models discrimination was assessed using c-statistics and calibration assessed via calibration plots and the Hosmer and Lemeshwow (H-L) statistics. The optimal score was based on the Youden's index. RESULTS: A total of 2250 patients (men 57.2%) with a mean age of 35.8 years were included; among whom 213 deaths (cumulative incidence 9.5%) were recorded. Clinical form of tuberculosis (C), age (A, years), adjusted body mass index (B, BMI, kg/m2) and status for HIV (Human immunodefiency virus) infection (I) were significant predictors in the final model (p < 0.0001) which was of the form Death risk = 1/(1 + e - (-1.3120 + 0.0474 ∗ age - 0.1866 ∗ BMI + 1.1637 (if smear negative TB) + 0.5418(if extra - pulmonary TB) + 1.3820(if HIV+))). The c-statistic was 0.812 in the derivation sample and 0.808 after correction for optimism. The calibration was good [H-Lχ2 = 6.44 (p = 0.60)]. The optimal absolute risk threshold was 4.8%, corresponding to a sensitivity of 81% and specificity of 67%. CONCLUSIONS: The preliminary promising findings from this study require confirmation through independent external validation studies. If confirmed, the model derived could facilitate the stratification of TB patients for mortality risk and implementation of additional monitoring and management measures in vulnerable patients.
- ItemOpen AccessFactors associated with contraceptive use in a rural area in Western Cape Province(2013) Peer, N; Morojele, N; London, LBACKGROUND: Safe and effective contraceptive use can substantially improve women's reproductive health. Although the contraceptive prevalence rate (CPR) in South Africa is comparable to rates globally, inequalities in CPR affect poor and rural women. This study aimed to determine the CPR and factors associated with contraceptive use in a rural district of Western Cape Province. METHOD: Cross-sectional survey data based on 412 face-to-face interviews with female participants between 18 and 44 years of age were collected in 2006 for a primary fetal alcohol syndrome prevention study in a rural district in Western Cape Province. The study used effective contraception (ECC) as the outcome variable. ECC included use of oral contraceptives, condoms, injectables or sterilisation. Independent variables included socio-demographic factors, substance use, psychosocial factors, community factors, childbearing characteristics and partner characteristics. RESULTS: Women were more likely to use ECC if they reported high self-esteem (compared with low or moderate self-esteem (prevalence risk ratio (PRR)=1.23; 95% confidence interval (CI) 0.99 - 1.53); if they strongly or moderately agreed that their culture entitled men to make decisions regarding child-bearing compared with those who disagreed (PRR=1.28; 95% CI 0.96 - 1.71); and if they had one child or more compared with no children (PRR=1.62; 95% CI 1.24 - 2.11). CONCLUSION: The CPR for sexually active women in this study was low at 39.3%. To promote contraceptive use in similar rural populations, family planning programmes should focus on increasing men's approval of contraception, improving partner communication around family planning and bolstering women's confidence in their reproductive decision-making, and particularly their self-esteem. There should be greater focus on nulliparous women.
- ItemOpen AccessHIV risk perception and behavior among medically and traditionally circumcised males in South Africa(2016) Zungu, N P; Simbayi, L C; Mabaso, M; Evans, M; Zuma, K; Ncitakalo, N; Sifunda, SAbstract Background In South Africa, voluntary medical male circumcision (VMMC) has recently been implemented as a strategy for reducing the risk of heterosexual HIV acquisition among men. However, there is some concern that VMMC may lead to low risk perception and more risky sexual behavior. This study investigated HIV risk perception and risk behaviors among men who have undergone either VMMC or traditional male circumcision (TMC) compared to those that had not been circumcised. Methods Data collected from the 2012 South African national population-based household survey for males aged 15 years and older were analyzed using bivariate and multivariate multinomial logistic regression, and relative risk ratios (RRRs) with 95 % confidence interval (CI) were used to assess factors associated with each type of circumcision relative no circumcision. Results Of the 11,086 males that indicated that they were circumcised or not, 19.5 % (95 % CI: 17.9–21.4) were medically circumcised, 27.2 % (95 % CI: 24.7–29.8) were traditionally circumcised and 53.3 % (95 % CI: 50.9–55.6) were not circumcised. In the final multivariate models, relative to uncircumcised males, males who reported VMMC were significantly more likely to have had more than two sexual partners (RRR = 1.67, p = 0.009), and males who reported TMC were significantly less likely to be low risk alcohol users (RRR = 0.72, p < 0.001). Conclusion There is a need to strengthen and improve the quality of the counselling component of VMMC with the focus on education about the real and present risk for HIV infection associated with multiple sexual partners and alcohol abuse following circumcision.
- ItemOpen AccessLack of paradoxical bronchoconstriction after administration of tiotropium via Respimat® Soft Mist™ Inhaler in COPD(2011) Hodder, Rick; Lee, Angela; Bateman, EricBronchoconstriction has been reported in asthma and chronic obstructive pulmonary disease (COPD) patients after administration of some aqueous inhalation solutions. We investigated the incidence of this event during long-term clinical trials of tiotropium delivered via Respimat® Soft Mist™ Inhaler (SMI). We retrospectively analyzed pooled data from two identical Phase III clinical trials, in which 1990 patients with COPD received 48 weeks’ treatment with once-daily tiotropium (5 or 10 μg) or placebo inhaled via Respimat® SMI. We recorded the incidence of bronchospasm and of a range of respiratory events that could suggest bronchoconstriction during the first 30 minutes after inhalation of study treatment on each of the eight test days. No patients reported bronchospasm. Six patients (0.3%) reported a combination of at least two events suggestive of bronchoconstriction, and 21 (1.1%) reported either rescue medication use or a respiratory adverse event. Asymptomatic falls in forced expiratory volume in one second (FEV1) of ≥15% were recorded on all test days, with no change in incidence over time, and affected 8.2% of those in the tiotropium groups and 14.5% of those on placebo. In COPD patients receiving long-term treatment with tiotropium 5 or 10 μg via Respimat® SMI, no bronchospasm was recorded, and the number of events possibly indicative of paradoxical bronchoconstriction was very low.
- ItemOpen AccessNo evidence for association of insulin receptor substrate-1 Gly972Arg variant with type 2 diabetes mellitus in a mixed-ancestry population of South Africa(2014) Vergotine, Zelda; Kengne, André Pascal; Erasmus, Rajiv Timothy; Matsha, Tandi EdithBACKGROUND: The most common single-nucleotide polymorphism in the insulin receptor substrate-1 (IRS1) gene is Gly972Arg, which is associated with a 25% increased risk of developing diabetes. The mixed-ancestry population of South Africa (SA) has one of the highest prevalences of type 2 diabetes mellitus (T2DM) in Africa. OBJECTIVE: To report the frequency of IRS1 Gly972Arg and investigate its associations with cardiometabolic traits. METHODS: DNA from 856 mixed-ancestry adults drawn from an urban community of Bellville South, Cape Town, SA, was genotyped by two independent laboratories. Oral glucose tolerance tests were performed and cardiometabolic risk factors measured. RESULTS: A total of 237 (24.7%) participants had T2DM. The IRS1 Gly972Arg variant was present in 7.9% of the individuals studied and only one participant (non-diabetic) carried the homozygous A/A variant. In linear and logistic regression analyses, Gly972Arg was not associated with obesity, insulin resistance/sensitivity or T2DM. CONCLUSIONS: The prevalence of the Gly972Arg variant in the mixed-ancestry population of SA is comparable to that reported in African Americans, but its presence is not associated with cardiometabolic traits. This suggests that the Gly972Arg variant may not aid diabetes risk evaluation in this setting, nor can such information help explain the high prevalence of diabetes previously reported in this population.
- ItemOpen AccessReasons for poor follow-up of diabetic retinopathy patients after screening in Tanzania: a cross-sectional study(2016) Mtuya, Christina; Cleland, Charles R; Philippin, Heiko; Paulo, Kidayi; Njau, Bernard; Makupa, William U; Hall, Claudette; Hall, Anthony; Courtright, Paul; Mushi, DeclareAbstract Background Diabetes is an emerging public health problem in sub-Saharan Africa. Diabetic retinopathy is the commonest microvascular complication of diabetes and is a leading cause of blindness, mainly in adults of working age. Follow-up is crucial to the effective management of diabetic retinopathy, however, follow-up rates are often poor in sub-Saharan Africa. The aim of this study was to assess the proportion of patients not presenting for follow-up and the reasons for poor follow-up of diabetic patients after screening for retinopathy in Kilimanjaro Region of Tanzania. Methods All diabetic patients referred to a tertiary ophthalmology hospital after screening for retinopathy in 2012 were eligible for inclusion in the study. A randomly selected group of patients from the community-based diabetic retinopathy screening register were identified; among this group, follow-up was assessed. Interviews were conducted within this group to inform on the reasons for poor follow-up. Results Among the 203 patients interviewed in the study 50 patients (24.6 %) attended the recommended referral appointment and 153 (75.4 %) did not. Financial reasons were self-reported by 35.3 % of those who did not attend the follow-up appointment as the reason for non-attendance. Multiple logistic regression analysis showed that the patient report of the clarity of the referral process (p = 0.014) and the patient report of whether a healthcare worker told the patient that diabetic retinopathy could be treated (p = 0.005) were independently associated with attendance at a follow-up appointment. Income per month was not associated with attendance at a follow-up appointment on multivariate analysis. Conclusions Financial factors are commonly cited as the reason for non-compliance with follow-up recommendations. However, the reasons for poor compliance are likely to be more complicated. This study highlights the importance of health system factors. Improving the clarity of the referral process and frequent reminders to patients that diabetic retinopathy can be treated are practical strategies that should be incorporated into screening programmes to increase attendance at subsequent follow-up appointments. The results from this study are applicable to other screening programmes as well as those for diabetic retinopathy.
- ItemOpen AccessThe Clostridium difficile problem: A South African tertiary institution's prospective perspective(2013) Rajabally, N M; Pentecost, M; Pretorius, G; Whitelaw, A; Mendelson, M; Watermeyer, GBACKGROUND AND OBJECTIVES: The aim of this study is to report the incidence of Clostridium difficile-associated disease (CDAD) in a tertiary-care hospital in South Africa and to identify risk factors, assess patient outcomes and determine the impact of the hypervirulent strain of the organism referred to as North American pulsed-field type 1 (NAP1). METHODS: Adults who presented with diarrhoea over a period of 15 months were prospectively evaluated for CDAD using stool toxin enzyme immunoassay (EIA). Positive specimens were evaluated by PCR. Patient demographics, laboratory parameters and outcomes were analysed. RESULTS: CDAD was diagnosed in 59 (9.2%) of 643 patients (median age 39 years, IQR 30 - 55). Thirty-four (58%) were female. Recent antibiotic exposure was reported in 39 (66%), 27 (46%) had been hospitalised within 3 months, and 14 (24%) had concomitant inflammatory bowel disease (IBD). Nineteen (32%) had community-acquired CDAD (CA-CDAD). The annual incidence of hospital-acquired CDAD (HA-CDAD) was 8.7 cases/10 000 hospitalisations. Two cases of the hypervirulent strain NAP1 were identified. Seven (12%) patients underwent colectomy (OR 6.83; 95% CI 2.41 - 19.3). On logistic regression, only antibiotic exposure independently predicted for CDAD (OR 2.9; 95% CI 1.6 - 5.1). Three (16%) cases of CA-CDAD reported antibiotic exposure (v. 90% of HA-CDAD, p<0.0001). Twelve (86%) patients had concomitant IBD (p<0.0001 v. HA-CDAD). CA-CDAD was significantly associated with antibiotic exposure (OR 0.04, 95% CI 0.01 - 0.24) and IBD (OR 9.6, 95% CI 1.15 - 79.8). CONCLUSION: The incidence of HA-CDAD in the South African setting is far lower than that reported in the West. While antibiotic use was a major risk factor for HA-CDAD, CA-CDAD was not associated with antibiotic therapy. Concurrent IBD was a predictor of CA-CDAD.