Prevalence of Falls in an Urban Community-Dwelling Older Population of Cape Town, South Africa

OBJECTIVE

Falls are a major cause of disability and mortality in older adults. Studies on falls in this population have mainly been conducted in high income countries, and scant attention has been given to the problem in low and middle income countries, including South Africa. The aim of the study was to establish a rate for falls in older adults in South Africa.

DESIGN

A cross-sectional survey with a 12-month follow-up survey.

SETTING

Three purposively selected suburbs of Cape Town: Plumstead, Wynberg Central and Gugulethu.

PARTICIPANTS

Eight hundred and thirty seven randomly sampled ambulant community-dwelling subjects aged ≥ 65 years grouped according to ethnicity in three sub-samples: black Africans, coloureds (people of mixed ancestry) and whites.

MEASUREMENTS

Data were collected on socio-demographic and health characteristics, and history of falls using a structured questionnaire and a protocol for physical assessments and measurements.

RESULTS

Of the total baseline (n=837) and follow-up (n=632) survey participants, 76.5% and 77.2 % were females with a mean (S.D) age of 74 years (6.4) and 75 years (6.2), respectively. Rates of 26.4% and 21.9% for falls and of 11% and 6.3% for recurrent falls, respectively, were calculated at baseline and follow-up. Fall rates differed by ethnic sub-sample at baseline: whites 42 %, coloureds 34.4% and black Africans 6.4 % (p=0.0005). Rates of 236, 406 and 354 falls per 1000 person years were calculated for men, women and both genders, respectively. Recurrent falls were more common in women than in men.

CONCLUSION

Falls are a significant problem in older adults in South Africa. Effective management of falls and falls prevention strategies for older people in South Africa, need to be developed and implemented.

Diagnostic accuracy of clinical signs used to identify electrolyte disturbances in children with diarrhoea

BACKGROUND

No studies have assessed the diagnostic accuracy of clinical signs of electrolyte disturbances in children with dehydrating diarrhoea.

AIMS

To assess the diagnostic accuracy and reliability of clinical signs previously reported to be associated with plasma sodium and potassium disturbances in children.

METHODS

A cross-sectional analytical study of 476 children aged 6 weeks to 2 years, admitted to a rehydration unit in Cape Town, South Africa. The clinical signs were elicited on admission by one of 58 junior doctors. Operational definitions of clinical signs were provided, but no additional training was given. Admission plasma electrolyte levels were the reference standard. Likelihood ratios were the primary measures of diagnostic accuracy, with reliability expressed as weighted Kappa scores.

RESULTS

Inter-observer agreement was generally poor, and confidence intervals were wide. None of the 18 signs studied had clinically meaningful diagnostic accuracy even for severe plasma sodium and potassium abnormalities.

CONCLUSIONS

None of the clinical signs assessed were useful in clinical practice. Additional training would improve the accuracy of the signs.

Therapeutic impact of routine electrolyte testing in childhood diarrhoea

AIM

To report on the management of plasma sodium and potassium disturbances, identified by routine electrolyte testing in children.

METHODS

A prospective cohort study of patients admitted to the Diarrhoea Rehydration Unit of Red Cross Children's Hospital, Cape Town, South Africa. The patients were 530 children aged 6 weeks to 2 years with a primary diagnosis of diarrhoea.

RESULTS

For plasma sodium levels <125 mmol/L (3.4%, 95% CI 2.0-0 5.3), 48 patients (95% CI 30-116) needed testing for one to receive a change of management. For plasma potassium levels <3 mmol/L (31.6%, 95% CI 27.6-35.6), fewer patients (6, 95% CI 5-7) needed testing for one to receive a change of management.

CONCLUSION

Electrolyte abnormalities were detected and clinical management changed, but large numbers of patients needed to be tested for each change of management.

Conjugate vaccines for preventing Haemophilus influenzae type B infections

BACKGROUND

Haemophilus influenzae (H. influenzae) is an important cause of meningitis and pneumonia in children. Vaccine cost is a significant barrier to use in low income countries. Determining the size of the effects of the vaccine will enable cost-effectiveness comparisons with competing priorities in low income countries.

OBJECTIVES

1. To determine the effects of conjugate Hib vaccine in preventing Hib disease or death in children under five years of age.2. To determine any variation in effect with type of vaccine, number of doses, age at first dose, in children with known HIV infection, or in high and low income countries.3. To determine any serious adverse outcomes.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 4, 2006); MEDLINE (January 1966 to December 2006); EMBASE (1990 to June 2006) and scanned reference lists and contacting of authors of trial reports. Reports in all languages were considered.

SELECTION CRITERIA

All randomised controlled trials (RCTs) or quasi-RCTs of conjugate H. influenzae type b vaccines compared with placebo or no treatment in children who were followed until at least two years of age.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected eligible studies and extracted data.

MAIN RESULTS

Six studies were included in the review, and four in the meta-analyses. The overall quality of the trials was good. The relative risk for invasive Hib disease was 0.20 (95% confidence interval (CI) 0.07 to 0.54; random-effects model), but there was statistically significant unexplained variation (heterogeneity) in the effects of the four trials in the meta-analysis (P = 0.002). The size of the effects did not appear to differ consistently with different vaccine types, the number of vaccine doses, age at first vaccination or use in high income versus low income countries, but the CIs for the effect estimates were wide. Hib-related mortality data showed a non-significant trend towards benefit (relative risk was 0.29; 95% CI 0.07 to 1.20; random-effects model). The relative risk for all cause mortality in the two trials from which data were available were 1.01 (95% CI 0.38 to 2.67, random-effects model) and 0.97. No serious adverse effects were reported in any of the trials.

AUTHORS' CONCLUSIONS

Hib vaccine is safe and effective. In resource-poor settings, decisions to use the vaccine will depend on its cost, the local burden of Hib disease and competing priorities.

Conjugate vaccines for preventing Haemophilus influenzae type b infections

BACKGROUND

Haemophilus influenzae (H. influenzae) is an important cause of meningitis and pneumonia in children, causing an estimated three million cases of serious disease and hundreds of thousands of deaths annually worldwide. The introduction of H. influenzae type b (Hib) vaccines into routine immunisation schedules in developed countries has been followed by a rapid decline in disease occurrence, but vaccine cost is a significant barrier to use in developing countries. There is a need to determine the size of the effects of the vaccine, to enable cost-effectiveness comparisons with competing priorities in developing countries.

OBJECTIVES

1. To determine the effects of conjugate Hib vaccine in preventing Hib disease or death in children under five years.2. To determine any serious adverse outcomes.

SEARCH STRATEGY

Searches of the Cochrane Central Register of Controlled Trials (CENTRAL) (issue 1, 2003); MEDLINE (January 1966 to April 2003), EMBASE (1990 to April 2003); and scanning of reference lists and contacting of authors of trial reports. Reports in all languages were considered.

SELECTION CRITERIA

All randomised controlled trials or quasi-randomised trials of conjugate H. influenzae type b vaccines compared with placebo or no treatment in children who were followed until at least two years of age.

DATA COLLECTION AND ANALYSIS

Two investigators independently selected eligible studies and extracted data. Differences were resolved by discussion.

MAIN RESULTS

Five studies were included in the review, and four in meta-analyses. The overall quality of the trials was good. The relative risk for invasive Hib disease was 0.20 (95% confidence interval 0.07 to 0.54; random effects model), but there was statistically significant unexplained variation (heterogeneity) in the effects of the four trials in the meta-analysis (p = 0.002). The size of the effects found in the trials did not appear to differ consistently with different vaccine types, the number of vaccine doses, age at first vaccination or use in developed vs developing countries, but the confidence intervals for the effect estimates were wide.Hib-related mortality data showed a non-significant trend towards benefit (relative risk was 0.29; 95% confidence interval 0.07 to 1.20; random effects model). The relative risk for all cause mortality in the single trial from which data were available was 1.01 (95% confidence interval 0.38 to 2.67, random effects model). No serious adverse effects were reported in any of the trials, involving a total of 257,000 infants.

REVIEWER'S CONCLUSIONS

Hib vaccine is safe and effective. The size of the effect could plausibly be anywhere between a 46% and 93% reduction in Hib invasive disease, before the effect of herd immunity is taken into account. In resource-poor settings, decisions to use the vaccine will depend on its cost, the local burden of Hib disease and competing priorities. Insufficient evidence from randomised controlled trials was identified of the effects of Hib conjugate vaccine on either Hib-specific or on all-cause mortality.

Symptomatic treatment of the cough in whooping cough

BACKGROUND

Whooping cough is an important cause of childhood morbidity and mortality. There are 20 to 40 million cases of whooping cough annually world-wide, 90% of which occur in developing countries, resulting in an estimated 200 to 300 000 fatalities each year. Much of the morbidity is due to the effects of the paroxysmal cough. Corticosteroids, salbutamol (beta 2 - adrenergic stimulant), and pertussis-specific immunoglobulin have been proposed as standard treatment for the cough. Antihistamines have also been administered. No systematic review of the effectiveness of any of these interventions or others has been performed.

OBJECTIVES

To assess the effectiveness and safety of interventions used to reduce the severity of the coughing paroxysms in whooping cough in children and adults.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (issue 2, 2003); MEDLINE (January 1966 to June 2003); EMBASE (1990 to June 2003) and LILACS (1982 to November 2001). We also scanned reference lists of identified trials and contacted authors of identified trials and relevant pharmaceutical companies.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials of any intervention aimed at suppressing the cough in whooping cough; excluding antibiotics and vaccines.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected studies and extracted data. Our primary outcome was frequency of paroxysms of coughing. Secondary outcomes were frequency of vomiting, frequency of whoop, frequency of cyanosis, development of serious complications, mortality from any cause, side effects due to medication, admission to hospital and duration of hospital stay. Disagreements were resolved by discussion.

MAIN RESULTS

Nine studies satisfied the inclusion criteria but four had insufficient data for meta - analysis of pre-specified outcomes. Studies were small and poorly reported. The largest study had a sample size of 49 and the smallest study 18. All studies were performed in industrialised settings. Eligible studies assessed diphenhyramine, pertussis immunoglobulin, dexamethasone and salbutamol. No statistically significant benefit was found for any of the interventions. Diphenhydramine did not change coughing spells (mean increase of coughing spells per 24 hours 1.9 with 95%CI - 4.7 to 8.5) and pertussis immunoglobulin no change in hospital stay (0.7 days 95% CI -3.8 to 2.4), and a mean reduction of 3.1 whoops per 24 hours [95% CI -6.2; 0.02]. Dexamethasone did not show a clear decrease in hospital stay (-3.5 days 95% CI - 15.3 to 8.4) and salbutamol showed no change in coughing paroxysms per 24 hours [-0.22 95% CI - 4.13 to 3.69].

REVIEWER'S CONCLUSIONS

Insufficient evidence exists to draw conclusions about the effects of any intervention for the cough in whooping cough.

Cotrimoxazole prophylaxis for opportunistic infections in children with HIV infection

BACKGROUND

The prevention and early treatment of infections are the mainstay of the medical management of the majority of children with HIV infection, who live in low income countries without access to antiretroviral drugs. Cotrimoxazole is cheap and effective against a wide range of organisms, including Pneumocystis carinii pneumonia (PCP) which is an important cause of death and illness in the first year of life. It is safe with relatively few side-effects. Diagnosis of HIV in children is complicated by the presence of maternal antibodies in early life and providing prophylaxis based initially on maternal status is one possible solution. However routine prophylactic treatment is difficult to deliver in low-resource settings, and could also lead to increased resistance to the drug.

OBJECTIVES

To assess the effects of routinely administered cotrimoxazole on death and illness episodes in children with HIV infection, and in infants of HIV infected mothers.

SEARCH STRATEGY

We searched the Cochrane HIV/AIDS registry, MEDLINE, the Cochrane Controlled Trials Register, LILACS, AIDSLINE, AIDSTRIALS and AIDSDRUGS databases, and proceedings and abstracts from AIDS and TB conferences (search date July 2001). We checked reference lists of pertinent articles, and contacted pharmaceutical companies and experts in the field.

SELECTION CRITERIA

Randomised or quasi randomised trials comparing routinely administered cotrimoxazole versus placebo or no treatment in children (age less than 13 years) with HIV infection, or children less than 18 months with HIV infected mothers.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial eligibility and quality.

MAIN RESULTS

No studies were found that fulfilled the selection criteria.

REVIEWER'S CONCLUSIONS

No evidence from controlled trials was found of the effect of cotrimoxazole prophylaxis in HIV-infected children.

Seasonal plasma electrolyte fluctuations in childhood diarrhoea

A retrospective analysis of routinely collected data from a diarrhoea rehydration unit found clinically meaningful parallel seasonal variation in plasma sodium and potassium concentrations. The prevalence of severe hypokalaemia was 7.2% and 0.4% in February and August respectively, and of severe hypernatraemia 0.4% and 5.0% respectively. These unexpected findings need prospective confirmation and exploration in other settings.

Observer variation in detecting lymphadenopathy on chest radiography

OBJECTIVE

To assess inter- and intra-observer agreement in the detection of lymphadenopathy on chest radiography in children at risk for tuberculosis.

PATIENTS AND METHODS

Retrospective examination of the antero-posterior and lateral chest radiographs of children aged 1 month to 11 years discharged from the short-stay ward of the Red Cross Children's Hospital, Cape Town, with a diagnosis of tuberculosis or pneumonia. Four paediatric pulmonologists viewed the radiographs independently. The main outcome measures were inter- and intra-observer agreement on the presence or absence of lymphadenopathy, reported as present, absent or equivocal, and expressed as weighted kappa statistics.

RESULTS

Weighted kappa for the six pairs of observers ranged from 0.14 (95%CI 0.02-0.30) to 0.52 (95%CI 0.35-0.69). After a 3-month interval, intra-observer agreement ranged from 0.44 (95%CI 0.25-0.62) to 0.71 (95%CI 0.56-0.87). The average weighted kappa for inter-observer agreement was 0.33, and the average intra-observer kappa was 0.55.

CONCLUSIONS

There was 'fair' inter- and 'moderate' intra-observer agreement among paediatric pulmonologists in detecting lymphadenopathy on chest radiography in children. Caution is necessary when basing clinical decisions on the presence of lymphadenopathy on chest radiography.

Evidence for action? Patterns of clinical and public health research on tuberculosis in South Africa, 1994-1998

OBJECTIVES

To describe patterns of clinical and public health research into tuberculosis in South Africa from 1994-1998, and to assess the quality of studies of diagnostic accuracy and treatment.

DESIGN

MEDLINE and the African Health Anthology were searched for journal articles published from 1994-1998 reporting clinical and public health research into tuberculosis in South Africa. Information extracted from the reports included research setting, study design, aspects of the quality of study design and reporting, and evidence of attention to statistical power.

RESULTS

One hundred and thirty-five eligible studies were identified; 39 (28.9%) of the studies were case reports or case series. Important methodological flaws were identified in studies of diagnosis and treatment that compromised the validity of the study results. Of the 28 studies assessing interventions, 10 (35.7%) were randomised controlled trials with only one reporting adequate allocation. Of the 34 studies assessing diagnosis, 16 (47.0%) were cross-sectional assessments of diagnostic accuracy, and none reported that comparison of the reference standard was independent or blind. Fifty-four (79.4%) of the analytical studies with statistically non-significant results showed no evidence of consideration of sample size.

CONCLUSION

The usefulness of tuberculosis research in South Africa is compromised by the questionable validity of many studies and a lack of attention to sample size.

Respiratory syncytial virus infection in children hospitalised with acute lower respiratory tract infection

BACKGROUND

Data are lacking on respiratory syncytial virus. (RSV) respiratory tract infections in children from developing countries.

OBJECTIVE

To determine the importance of RSV as a cause of acute lower respiratory tract infection (ALRTI) in Cape Town children.

METHODS

Children younger than 2 years of age admitted to hospital with ALRTI over a 15-month period from 1 June 1995 to 31 August 1996 were studied prospectively. Sociodemographic data, risk factors for severe RSV disease, clinical signs, diagnosis and hospital course were documented. A nasopharyngeal aspirate (NPA) for detection of RSV by enzyme immunoassay (EIA) was obtained in all cases. The NPA of every fifth child was sent for viral culture.

RESULTS

A total of 1,288 patients (60% male, 40% female) with a median age (25th-75th percentile) of 6 months (2-11 months) was enrolled; 32.4 had one or more risk factors for severe RSV infection. Pneumonia was diagnosed in 62.2%, bronchiolitis in 20.6%, laryngotracheobronchitis (LTB) in 8% and other respiratory illnesses in 9.2%. Mild disease, requiring admission to an overnight ward, was documented in 38.1%, while 48.9% and 13% respectively had moderate and severe disease requiring admission to a general ward and intensive care unit (ICU). Supplemental oxygen and mechanical ventilation were required by 68.9% and 8.5% of patients, respectively. The median duration of hospital stay was 5 days (range 1-10 days). RSV EIA was positive in 16.4% of cases, and there was no difference in detection rates according to diagnosis. Viral culture performed in 162 of the 1,288 study patients (12.6%) grew RSV in 11.7% of cases, adenovirus in 3.7%, para-influenza virus type 3 in 2.5% and influenza B virus in 0.6%. Patients who tested RSV EIA-positive did not significantly differ from those who tested negative with regard to demographic variables, clinical diagnoses, risk factors for RSV or length of hospitalisation. The only significant difference noted was the presence of hyperinflation, which occurred in 70.1% of EIA-positive patients compared with 57.1% of those testing negative (P = 0.0005). The mortality rate (2%) was similar for both groups.

CONCLUSION

This study indicates that RSV is an important cause of hospitalisation in infants and young children with ALRTI. Distinguishing RSV from other ALRTIs is difficult because of similarity in clinical presentation among children.

An audit of the use of antibiotics in presumed viral meningitis in children

The antibiotic management of 139 consecutive patients with presumed viral meningitis evaluated during a 6-month period was examined. The presumptive diagnosis of viral meningitis was made in retrospect by consensus among the authors, using clinical and routinely available laboratory information. Sixty-eight (51.9%) of 131 patients with complete records were treated with antibiotics after diagnosis, 25 for 2 days or less and 43 for longer than 2 days. Antibiotic treatment was retrospectively judged to be unjustified in 35 (81.4%) of the 43 patients treated for longer than 2 days. When compared with untreated patients antibiotic treatment was started in younger female children with lower cerebrospinal fluid glucose values and longer duration of symptoms. There was no difference between the two groups in other cerebrospinal fluid values, peripheral white blood cell count or history of preceding antibiotics. In contrast no associations were found with treatment beyond 2 days, compared with treatment for 2 days or less. Thus the decision to stop antibiotic treatment early did not appear to be made according to consistent clinical criteria. This apparent lack of consistent criteria suggests the need to develop clinical guidelines for such decisions, both to aid clinicians and to provide standards for medical audit.