Have we improved use of medicines in developing and transitional countries and do we know how to? Two decades of evidence.

OBJECTIVE: To assess progress in improving use of medicines in developing and transitional countries by reviewing empirical evidence, 1990-2009, concerning patterns of primary care medicine use and intervention effects. METHODS: We extracted data on medicines use, study setting, methodology and interventions from published and unpublished studies on primary care medicine use. We calculated the medians of six medicines use indicators by study year, country income level, geographic region, facility ownership and prescriber type. To estimate intervention impacts, we calculated greatest positive (GES) and median effect sizes (MES) from studies meeting accepted design criteria. RESULTS: Our review comprises 900 studies conducted in 104 countries, reporting data on 1033 study groups from public (62%), and private (mostly for profit) facilities (26%), and households. The proportion of treatment according to standard treatment guidelines was 40% in public and <30% in private-for-profit sector facilities. Most indicators showed suboptimal use and little progress over time: Average number of medicines prescribed per patient increased from 2.1 to 2.8 and the percentage of patients receiving antibiotics from 45% to 54%. Of 405 (39%) studies reporting on interventions, 110 (27%) used adequate study design and were further analysed. Multicomponent interventions had larger effects than single component ones. Median GES was 40% for provider and consumer education with supervision, 17% for provider education alone and 8% for distribution of printed education materials alone. Median MES showed more modest improvements. CONCLUSIONS: Inappropriate medicine use remains a serious global problem.

Predictors of antibiotic use in African communities: evidence from medicines household surveys in five countries.

OBJECTIVES: To investigate antibiotic use in five national household surveys conducted with the WHO methodology to identify key determinants of antibiotic use in the community. METHODS: Data from The Gambia, Ghana, Kenya, Nigeria and Uganda surveys were combined. We used logistic regression models that accounted for the clustered survey design to identify the determinants of care seeking outside the home and antibiotic use for 2914 cases of recent acute illness. RESULTS: Overall, 95% of individuals with acute illness took medicines, 90% sought care outside their homes and 36% took antibiotics. In multivariate analyses, illness severity was a strong predictor of seeking care outside the home. Among those who sought outside care, the strongest predictor of antibiotic use was the presence of upper respiratory symptoms (OR: 3.02, CI: 2.36-3.86, P<0.001), followed by gastrointestinal symptoms or difficulty breathing, and antibiotics use was less likely if they had fever. The odds of receiving antibiotics were higher when visiting a public hospital or more than one healthcare facility. CONCLUSIONS: The nature and severity of symptoms and patterns of care seeking had the greatest influence on decisions to take antibiotics. Antibiotics were widely available and inappropriately used in all settings. Policies to regulate antibiotics distribution as well as interventions to educate prescribers, dispensers and consumers are needed to improve antibiotic use.

Medicine prices, availability, and affordability in 36 developing and middle-income countries: a secondary analysis.

BACKGROUND: WHO and Health Action International (HAI) have developed a standardised method for surveying medicine prices, availability, affordability, and price components in low-income and middle-income countries. Here, we present a secondary analysis of medicine availability in 45 national and subnational surveys done using the WHO/HAI methodology. METHODS: Data from 45 WHO/HAI surveys in 36 countries were adjusted for inflation or deflation and purchasing power parity. International reference prices from open international procurements for generic products were used as comparators. Results are presented for 15 medicines included in at least 80% of surveys and four individual medicines. FINDINGS: Average public sector availability of generic medicines ranged from 29.4% to 54.4% across WHO regions. Median government procurement prices for 15 generic medicines were 1.11 times corresponding international reference prices, although purchasing efficiency ranged from 0.09 to 5.37 times international reference prices. Low procurement prices did not always translate into low patient prices. Private sector patients paid 9-25 times international reference prices for lowest-priced generic products and over 20 times international reference prices for originator products across WHO regions. Treatments for acute and chronic illness were largely unaffordable in many countries. In the private sector, wholesale mark-ups ranged from 2% to 380%, whereas retail mark-ups ranged from 10% to 552%. In countries where value added tax was applied to medicines, the amount charged varied from 4% to 15%. INTERPRETATION: Overall, public and private sector prices for originator and generic medicines were substantially higher than would be expected if purchasing and distribution were efficient and mark-ups were reasonable. Policy options such as promoting generic medicines and alternative financing mechanisms are needed to increase availability, reduce prices, and improve affordability.

Increasing mammography utilization: a controlled study.

BACKGROUND: Despite the effectiveness of breast cancer screening for women older than 50 years of age, only about one third of these women in the United States receive annual mammography. PURPOSE: This study was designed to determine if a community-wide intervention could increase use of mammography screening for breast cancer. Secondary end points were determination of changes in women's knowledge and attitudes toward mammography and physicians' self-reported screening practices. METHODS: We conducted a controlled study from January 1987 through January 1990 in two eastern North Carolina communities--New Hanover County (the experimental community) and Pitt County (the control community). Before development and implementation of the intervention program in New Hanover County and after the program had been in operation for 1 year, 500 women of ages 50-74 years and all primary-care physicians in each community were interviewed by telephone. In these interviews, we determined the use of mammography for breast cancer screening and the knowledge and attitudes about it. We also established the number of screening mammograms performed in 1987 and 1989 in each county and reviewed medical records to determine the percentage of women the physicians had referred for mammograms. RESULTS: The percentage of women who reported receiving a mammogram in the previous year increased from 35% to 55% in the experimental community and from 30% to 40% in the control community (difference of differences, 10%; P = .03 after adjustment for race, education, age, and having a regular doctor; 95% confidence interval, 1%-18%). Increases were greater in New Hanover County regardless of age, race, income, and education. However, the increase was less for Black women than for White women, both overall and in most demographic subgroups. The total number of mammograms performed increased 89% in the experimental community and 45% in the control community. Women's knowledge about mammography changed little, but the intention to get a mammogram increased 30% in New Hanover County, compared with a 17% increase in Pitt County--a statistically significant difference (P < .01). Physician reports and medical record reviews in the two communities showed similar increases in the number of mammograms ordered. CONCLUSIONS: A community-wide effort to increase use of breast cancer screening was successful, but more work must be done to reach the National Cancer Institute's goal of annual mammograms for 80% of women of ages 50-74.

Controlled trial of interventions to increase testing and treatment for Helicobacter pylori and reduce medication use in patients with chronic acid-related symptoms.

BACKGROUND: Many symptomatic patients take proton pump inhibitors or histamine-2 blockers for years and those without gastro-oesophageal reflux disease might benefit from Helicobacter pylori eradication. AIM: To increase testing and treatment of H. pylori and reduce chronic use of proton pump inhibitors and histamine-2 blockers. METHODS: We conducted a three-armed controlled trial in 14 managed care practices. We included adults who used proton pump inhibitors or histamine-2 blockers for >1 year and excluded those with gastro-oesophageal reflux disease or previous endoscopy. We compared usual care (n = 312 patients from 6 practices) to low-intensity (n = 147 from 3 practices) and high-intensity (n = 122 from 5 practices) interventions. Low-intensity intervention consisted of guidelines, patient-lists, and a "toolkit"; high-intensity intervention added academic group detailing by a gastroenterologist with reinforcement by pharmacists. RESULTS: Compared with usual care, the high-intensity intervention increased H. pylori test-ordering (29% versus 9% at 12 months, P = 0.02). About half (23 of 58) of patients tested positive and 22 received eradication treatments. The high-intensity intervention decreased proton pump inhibitor use by 9% per year (P = 0.028), but did not alter histamine-2 blocker use. The low intensity intervention was ineffective. CONCLUSIONS: Providing guidelines, patient-lists, and toolkits was no better than usual care. Adding group detailing and pharmacist reinforcements led to improvements in H. pylori management and decreases in proton pump inhibitor use.

Timeliness and quality of care for elderly patients with acute myocardial infarction under health maintenance organization vs fee-for-service insurance.

BACKGROUND: A commonly voiced concern is that health maintenance organizations (HMOs) may withhold or delay the provision of urgent, essential care, especially for vulnerable patients like the elderly. OBJECTIVE: To compare the quality of emergency care provided in Minnesota to elderly patients with acute myocardial infarction (AMI) who are covered by HMO vs fee-for-service (FFS) insurance. METHODS: We reviewed the medical records of 2304 elderly Medicare patients who were admitted with AMI to 20 urban community hospitals in Minnesota (representing 91% of beds in areas served by HMOs) from October 1992 through July 1993 and from July 1995 through April 1996. MAIN OUTCOME MEASURES: Use of emergency transportation and treatment delay (>6 hours from symptom onset); time to electrocardiogram; use of aspirin, thrombolytics, and beta-blockers among eligible patients; and time from hospital arrival to thrombolytic administration (door-to-needle time). RESULTS: Demographic characteristics, severity of symptoms, and comorbidity characteristics were almost identical among HMO (n = 612) and FFS (n = 1692) patients. A cardiologist was involved as a consultant or the attending physician in the care of 80% of HMO patients and 82% of FFS patients (P = .12). The treatment delay, time to electrocardiogram, use of thrombolytic agents, and door-to-needle times were almost identical. However, 56% of HMO patients and 51% of FFS patients used emergency transportation (P = .02); most of this difference was observed for patients with AMIs that occurred at night (60% vs 52%; P = .02). Health maintenance organization patients were somewhat more likely than FFS patients to receive aspirin therapy (88% vs 83%; P = .03) and beta-blocker therapy (73% vs 62%; P = .04); these differences were partly explained by a significantly larger proportion of younger physicians in HMOs who were more likely to order these drug therapies. All differences were consistent across the 3 largest HMOs (1 staff-group model and 2 network model HMOs). Logistic regression analyses controlling for demographic and clinical variables produced similar results, except that the differences in the use of beta-blockers became insignificant. CONCLUSIONS: No indicators of timeliness and quality of care for elderly patients with AMIs were lower under HMO vs FFS insurance coverage in Minnesota. However, two indicators of quality care were slightly but significantly higher in the HMO setting (use of emergency transportation and aspirin therapy). Further research is needed in other states, in different populations, and for different medical conditions.

Reducing infections among women undergoing cesarean section in Colombia by means of continuous quality improvement methods.

BACKGROUND: Improving obstetric care in resource-limited countries is a major international health priority. OBJECTIVE: To reduce infection rates after cesarean section by optimizing systems of obstetric care for low-income women in Colombia by means of quality improvement methods. METHODS: Multidisciplinary teams in 2 hospitals used simple methods to improve their systems for prescribing and administering perioperative antibiotic prophylaxis. Process indicators were the percentage of women in whom prophylaxis was administered and the percentage of these women in whom it was administered in a timely fashion. The outcome indicator was the surgical site infection rate. RESULTS: Before improvement, prophylaxis was administered to 71% of women in hospital A; 24% received prophylaxis in a timely fashion. Corresponding figures in hospital B were 36% and 50%. Systems improvements included implementing protocols to administer prophylaxis to all women and increasing the availability of the antibiotic in the operating room. These improvements were associated with increases in overall and timely administration of prophylaxis (P<.001) in both hospitals by time series analysis, with adjustment for volume and case mix. After improvement, overall and timely administration of prophylaxis was 95% and 96% in hospital A and 89% and 96% in hospital B. In hospital A, the surgical site infection rate decreased immediately after the improvements (P<.001). In hospital B, the infection rate began a downward trend before the improvements that continued after their implementation (P =.04). CONCLUSION: Simple quality improvement methods can be used to optimize obstetric services and improve outcomes of care in resource-limited settings.

Geographic information systems: their use in environmental epidemiologic research.

Advances in geographic information system (GIS) technology, developed by geographers, provide new opportunities for environmental epidemiologists to study associations between environmental exposures and the spatial distribution of disease. A GIS is a powerful computer mapping and analysis technology capable of integrating large quantities of geographic (spatial) data as well as linking geographic with nongeographic data (e.g., demographic information, environmental exposure levels). In this paper we provide an overview of some of the capabilities and limitations of GIS technology; we illustrate, through practical examples, the use of several functions of a GIS including automated address matching, distance functions, buffer analysis, spatial query, and polygon overlay; we discuss methods and limitations of address geocoding, often central to the use of a GIS in environmental epidemiologic research; and we suggest ways to facilitate its use in future studies. Collaborative efforts between epidemiologists, biostatisticians, environmental scientists, GIS specialists, and medical geographers are needed to realize the full potential of GIS technology in environmental health research and may lead to innovative solutions to complex questions.

Effects on the immune system associated with living near a pesticide dump site.

In this paper, we report results of the second phase of a larger study designed to evaluate the effects on the immune system of living near a Superfund site containing organochlorine pesticides, volatile organic compounds, and metals. Phase II was conducted to determine whether living near the site, consisting of six locations in Aberdeen, North Carolina, is associated with higher plasma organochlorine levels, immune suppression, or DNA damage. Each of 302 residents of Aberdeen and neighboring communities provided a blood specimen, underwent a skin test, and answered a questionnaire. Blood specimens were analyzed for organochlorine pesticides, immune markers, and micronuclei. Of 20 organochlorines tested, only DDE was detected in the blood of participants (except for one individual). Age-adjusted mean plasma DDE levels were 4.05 ppb for Aberdeen residents and 2.95 ppb (p = 0.01) for residents of neighboring communities. Residents of 40-59 years of age who lived within a mile of any site, but particularly the Farm Chemicals site, had higher plasma DDE levels than residents who lived farther away. Residents who lived near the Farm Chemicals site before versus after 1985 also had higher plasma DDE levels. Overall, there were few differences in immune markers between residents of Aberdeen and the neighboring communities. However, residents who lived closer to the dump sites had statistically significantly lower mitogen-induced lymphoproliferative activity than residents who lived farther away (p < 0.05). Residential location was not consistently associated with frequency of micronuclei or skin test responses. Although some statistically significant differences in immune markers were noted in association with residential location, the magnitude of effects are of uncertain clinical importance.

Do waste incinerators induce adverse respiratory effects? An air quality and epidemiological study of six communities.

The purpose of the study presented here was to simultaneously measure air quality and respiratory function and symptoms in populations living in the neighborhood of waste incinerators and to estimate the contribution of incinerator emissions to the particulate air mass in these neighborhoods. We studied the residents of three communities having, respectively, a biomedical and a municipal incinerator, and a liquid hazardous waste-burning industrial furnace. We compared results with three matched-comparison communities. We did not detect differences in concentrations of particulate matter among any of the three pairs of study communities. Average fine particulate (PM2.5) concentrations measured for 35 days varied across study communities from 16 to 32 micrograms/m3. Within the same community, daily concentrations of fine particulates varied by as much as eightfold, from 10 to 80 micrograms/m3, and were nearly identical within each pair of communities. Direct measurements of air quality and estimates based on a chemical mass balance receptor model showed that incinerator emissions did not have a major or even a modest impact on routinely monitored air pollutants. A onetime baseline descriptive survey (n = 6963) did not reveal consistent community differences in the prevalence of chronic or acute respiratory symptoms between incinerator and comparison communities, nor did we see a difference in baseline lung function tests or in the average peak expiratory flow rate measured over a period of 35 days. Based on this analysis of the first year of our study, we conclude that we have no evidence to reject the null hypothesis of no acute or chronic respiratory effects associated with residence in any of the three incinerator communities.

Intervention research to promote clinically effective and economically efficient use of pharmaceuticals: the International Network for Rational Use of Drugs.

Despite acceptance of the essential drug concept by over 100 countries, current drug use patterns frequently result in unsafe use, waste of scarce resources, non-compliance, excess adverse drug reactions and disease resistance. Even in countries where resources for research are available, most efforts to improve drug prescribing have never been properly evaluated. Proposed interventions should reflect the behavioral basis for current drug use, target priority public health areas, and be feasible in developing country contexts. Most importantly, they must be critically assessed for cost and effectiveness in well-controlled field trials. The International Network for Rational Use of Drugs (INRUD) is a cooperative organization of health professionals and researchers in developing countries whose aim is to promote improved quality of care through more clinically effective and economically efficient use of pharmaceuticals. To accomplish this, INRUD will strengthen regional and national capacities to develop and scientifically evaluate programs to improve drug use and disseminate information on practical strategies shown to be cost-effective.

Changing behavior to maintain a healthy home.

Multidimensional strategies involving interpersonal interaction, strategic alliances and targeted use of the media have been shown experimentally to be the most effective behavioral change programs. Health providers need to communicate with schools and community groups, as well as work with product manufacturers and consumer and health organizations. Together these groups can collaborate with the media to communicate accurate information and guidance to the public. Planning effective public health and behavioral change campaigns involves diagnosis and identification of the target behavior. The intervention message must be focused, tested and refocused. Effective communication, crucial to public health campaigns, uses multiple channels and provides frequent repetition of the message.

Utilization of essential medications by vulnerable older people after a drug benefit cap: importance of mental disorders, chronic pain, and practice setting.

OBJECTIVE: To identify specific characteristics of patients, physicians, and treatment settings associated with decreased receipt of essential medications in a chronically ill, older population following a Medicaid three-prescription monthly reimbursement limit (cap). DESIGN: Quasi-experiment with bivariate and multivariate regression. SETTING: Patients in the New Hampshire Medicaid program and their regular prescribing physicians. PARTICIPANTS: Three hundred and forty-three chronically ill Medicaid enrollees with regular use of essential medications for heart disease, asthma/chronic obstructive pulmonary disease, diabetes mellitus, seizure, or coagulation disorders who received an average of three or more prescriptions per month during the baseline year. MEASUREMENTS: Postcap patient-level change in standard monthly dose of essential medications compared with the baseline period, presence of 11 comorbidities (defined by regular use of specific indicator drugs), practice setting, and location of regular prescribing physician. RESULTS: The mean percentage change in standard doses of essential medications following the cap was -34.4%. Larger changes were significantly associated with several baseline measures: greater numbers of precap medications, greater numbers of comorbidities, longer hospitalizations, and greater use of ambulatory services. The three comorbidities associated with the largest relative reduction in essential drug use were psychoses/bipolar disorders, anxiety/sleep problems, and chronic pain. Patients of physicians in group practices, clinics, or hospitals tended to have smaller dose reductions than those whose physicians were in solo or small-group practice. CONCLUSIONS: Patients most at risk of reduced access to essential medications because of a reimbursement cap include those with multiple chronic illnesses requiring drug therapy, especially illnesses with a mental health component. Physicians in clinics or large group practices may have maintained patient medication regimens more effectively.

Effects of long-acting versus short-acting calcium channel blockers among older survivors of acute myocardial infarction.

OBJECTIVE: Recent studies have highlighted the potentially harmful effects of short-acting calcium channel blockers, especially of the dihydropyridine type, in patients with coronary heart disease. Some have argued that long-acting calcium channel blockers are safer, but few outcome data exist. The objective of the study was to compare the occurrence of adverse outcomes among recipients of long-acting versus short-acting calcium channel blockers, with dihydropyridines and non-dihydropyridines compared separately. SETTING: The New Jersey Medicare population. DESIGN: A retrospective cohort study using linked Medicare and drug claims data. PARTICIPANTS: Older survivors of acute myocardial infarction (MI) occurring in 1989 and 1990. Eligible subjects had survived at least 30 days after the MI, participated in Medicare and a drug benefits program, and were prescribed a single type of either a long-acting or a short-acting calcium channel blocker within 90 days after the MI. MEASUREMENTS: The two outcome measures were rates of all-cause mortality and cardiac rehospitalization. Using separate Cox regression models for dihydropyridines (nifedipine, nicardipine) and non-dihydropyridines (diltiazem, verapamil), we examined these outcomes for recipients of long-acting compared with short-acting calcium channel blockers. RESULTS: Of the 833 patients eligible for the study, 160 were prescribed long-acting and 673 short-acting calcium channel blockers. Clinical characteristics of long-acting and short-acting users were comparable. During 2 years of follow-up, 221 deaths and 300 rehospitalizations occurred. Controlling for age, sex, race, and indicators of disease severity and comorbidity, the relative risk of dying for recipients of long-acting, compared with short-acting, dihydropyridines was .42 (95% confidence interval (CI), 0.21-0.86). For cardiac rehospitalization, the relative risk was 0.57 (95% CI, 0.34-0.94). For the long-acting versus short-acting nondihydropyridines, the adjusted relative risk of dying was 1.43 (95% CI, 0.88-2.32), and for cardiac rehospitalization, .65 (95% CI, 0.40-1.05). CONCLUSION: Use of long-acting dihydropyridine calcium channel blockers after acute MI was associated with substantially lower rates of cardiac rehospitalization and death compared with use of their short-acting counterparts. More data are needed to address the possibility that long-acting, compared with short-acting, non-dihydropyridines could decrease rehospitalization rates but increase mortality.

A population-based study of xerophthalmia in the extreme North Province of Cameroon, West Africa.

OBJECTIVE: To obtain cross-sectional data on clinical and nutritional vitamin A deficiency from which to design appropriate intervention strategies. DESIGN: A population-based survey using multistage, cluster sampling. SETTING: Extreme North Province of Cameroon, West Africa. PARTICIPANTS: Children aged 0 to 5 years. MAIN OUTCOME MEASURES: Clinical signs of active xerophthalmia and dietary vitamin A intake. RESULTS: Of 5352 children examined, signs of active xerophthalmia were noted in 0.62%. Bitot's spots, corneal xerosis, and corneal ulceration were noted in 0.47%, 0.06%, and 0.12% of the subjects, respectively. Children with xerophthalmia had lower vitamin A intake scores when compared with age-matched controls and with a 20% systematic subsample of children. CONCLUSION: Xerophthalmia is a major public health problem in this region.

Do open formularies increase access to clinically useful drugs?

Before 1990 many state Medicaid programs maintained "restrictive" formularies, which denied reimbursement for unlisted prescription drugs. This type of formulary has been criticized for denying important medications to poor, medically needy persons. As part of the Omnibus Budget Reconciliation Act of 1990, restrictive formularies in Medicaid programs were disallowed. Based on research into the 200 top-selling prescription drugs in the United States, we conclude that eliminating Medicaid restrictive formularies improved access to a subset of the 200 best sellers, but that the majority of these products offered only questionable or no additional therapeutic benefit.

Use of antihypertensive drugs by Medicare enrollees: does type of drug coverage matter?

Research has demonstrated that Medicare beneficiaries with drug coverage consume more clinically essential drugs. However, generosity of coverage varies considerably across beneficiaries. This study examines the association between types of drug coverage and the consumption and cost per tablet of essential antihypertensive medications among beneficiaries with hypertension. The findings indicate that while both state- and employer-sponsored drug coverage are associated with greater consumption of antihypertensive drugs and lower out-of-pocket costs per tablet, private supplemental coverage is not associated with greater use and is associated with only slightly lower out-of-pocket costs than among noncovered beneficiaries.

Is breast self-examination predicted by knowledge, attitudes, beliefs, or sociodemographic characteristics?

The relationship of women's sociodemographic characteristics, knowledge, attitudes, and beliefs to breast self-examination (BSE) practice is not clear. We therefore studied these variables among older women at risk for developing breast cancer to determine which might be associated with the sensitivity, specificity, and frequency of BSE practice. We interviewed 300 women 40 to 68 years of age and measured BSE sensitivity and specificity using manufactured silicone breast models containing lumps. Of 54 variables and 10 scales examined univariately, six were associated with BSE sensitivity, one was negatively associated with specificity, and 10 were associated with frequency. No variable was associated with more than one component of BSE practice, and BSE frequency was not associated with BSE sensitivity or specificity. Using multivariate analysis, BSE sensitivity was best explained by type of employment, health interest, and perceived vulnerability to breast cancer, which accounted for approximately 16% of the variance. BSE frequency was best explained by intention to perform BSE, knowing how to perform BSE, using the correct method of BSE, self-confidence in the ability to perform BSE monthly, and self-confidence in the ability to find small lumps. These variables accounted for 27% of the variance. Sociodemographic characteristics, knowledge, attitudes, and beliefs poorly predicted how accurately women practiced BSE but somewhat better predicted how often women practiced BSE.

Blindness and eye disease in Kenya: ocular status survey results from the Kenya Rural Blindness Prevention Project.

A series of eight regional eye surveys were conducted in Kenya as part of the Kenya Rural Blindness Prevention Project. Each survey consisted of clinical examinations of about 1800 individuals selected by a random cluster sampling technique in geographically distinct and culturally homogeneous rural areas; 13,803 examinations were completed in all. Together these surveys provide the basis for national estimates of the prevalence and aetiology of visual loss and ocular pathology. The results showed that 0.7% of rural Kenyans are blind in the better eye by WHO standards, and another 2.5% suffer significant visual impairment. Rates of visual loss tend to increase five-fold in each 20-year age cohort. Females have higher prevalence of visual loss than males over age 20, and certain geographical areas have markedly higher rates. The commonest cause of both blindness and visual impairment is cataract, accounting for 38% of all visual loss. Trachoma (a localised problem), glaucoma, macular degeneration, and severe refractive errors follow cataract as leading causes of blindness in the better eye. Trauma, corneal scars of various causes, phthisis, and staphyloma are important causes of monocular blindness. Nutritional eye disease does not appear to be a problem of any magnitude in rural Kenya.

Prevalence and causes of low vision and blindness in the Extreme North Province of Cameroon, West Africa.

A survey to determine the prevalence and causes of blindness and visual impairment in the Extreme North Province of Cameroon was conducted in the Spring of 1992. A total of 10,647 people age 6 years and older was selected from a multi-stage, clustered sample stratified by ecological zone. The subjects were examined by ophthalmologist-led teams for visual acuity and ocular diseases. Approximately 1.2% of the sample was bilaterally blind by the World Health Organization classification (Category 3) of vision less than the ability to count fingers at 3 meters. Similarly to results found in other developing countries, senile cataract was the most common diagnosis encountered and the most frequent principal cause of low vision and blindness.