Direct healthcare cost and barriers to the medical management of primary open-angle glaucoma in healthcare facilities in Yaounde – Cameroon

INTRODUCTION

In Africa, the most common form of glaucoma is primary open-angle glaucoma (POAG), with a prevalence of 4.2% and an average age of 40–80 years.^[1] In Cameroon, this prevalence is 5.5%.^[2] Impaired visual function and blindness due to this disease are important determinants of quality of life, particularly in the elderly,^[3] making glaucoma a major public health problem. The management of glaucoma has a long-term socioeconomic impact worldwide^[4] and is expected to become a major cause of healthcare expenditure. The cost of treatment varies from country to country and depends on the severity of glaucoma.^[5] In the United States of America, the cost of therapeutic management of glaucoma is estimated at $2.5 billion per year, and direct costs at $1.9 billion.^[4] In Scotland in 2015, for example, the annual cost was 534 Euros per patient,^[6] while in Benin, the average monthly cost of medical treatment was estimated at between 28.15 and 169.35 Euros, encompassing direct and indirect treatment costs.^[7] It is known that an illness with a financial burden >40% of the household income is likely to have a negative impact on the family finances.^[8] As the universal health coverage system has not yet been fully implemented in Cameroon to date, this work aimed to estimate the direct annual cost of medical care for POAG to obtain information that could guide public authorities and heads of institutions to improve the care and follow-up of patients with this condition.

MATERIALS AND METHODS

RESULTS

Clinical characteristics and severity stages

The most comorbidities found were arterial hypertension (24.7%; n = 30) followed by type 2 diabetes (5.8%; n = 7). A total of 82 (67.2%) participants had no known comorbidity. Participants with one or more glaucoma-affected relatives represented 3.3% (n = 4) of the study population.

[Table 2] shows the clinical and paraclinical characteristics of the study population.

Table 2: Clinical and paraclinical characteristics of the study population.

Characteristics	Right eye	Left eye
	Mean±SD (Min–Max)	Mean±SD (Min–Max)
Visual acuity (LogMAR)	0.52±0.13 (0–2.6]	0.65±0.17 (0–2.6)
Intraocular pressure (mmHg)	23.5±6.6 (10–48]	23.5±8.6 (9–60)
Cup/disc	0.73±0.2 (0.2–1)	0.79±0.2 (0.2–1)
Visual field (MD)	1.9±6.6 ([−29]; −40)	13.6±6.2 ([−4]; −40)
Glaucoma severity	n	n
Severe glaucoma MD: >−12dB	63	64
Moderate glaucoma MD: <−12dB	1	0
Low glaucoma MD: <−6dB	58	58

MD: Mean deviation, dB: decibel, SD: Standard deviation, n: Number of eyes

The mean VA of the study population ranged from 0.52 (decimal value = 3/10) to 0.65 (decimal value = 2/10), that is, borderline VA according to the LogMAR scale. A high IOP, with a mean value of 23.5 mm Hg, was found. The cup/disc ratio was abnormal, ranging from 0.8 to 0.9. A large proportion of participants had an impaired visual field, with right and left eye values of 11.9 and 13.6, respectively. In the present series, more than half of the studied patients (52%) had severe glaucoma.

Regarding medical treatment, 60.7% (n = 74), 31.9% (n = 39), and 7.4% (n = 9) of participants were on monotherapy, bitherapy, and tritherapy, respectively. The combination of three drugs was only prescribed for patients with severe glaucoma.

Prostaglandin analogs (Travoprost and Latanoprost) were the most widely prescribed drugs, with a frequency of 71%, followed by β-blockers (Carteolol and Timolol) and carbonic anhydrase inhibitors with frequencies of 62% and 15%, respectively. The α-2 adrenergic antagonists were the least used drugs (2%) [Figure 1].

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Figure 1:

Distribution of ocular antihypertensives used by the study population.

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Evaluation of direct costs

Analysis of investigations shows that 275 consultations, 337 ocular pressure measurements, 195 fundus examinations, 90 visual fields, and 39 gonioscopy procedures were carried out during the year of the study. [Table 3] shows the average number of medical procedures performed on the study population, as well as the average cost of each procedure performed during the year.

Table 3: Medical procedures performed during the study period.

Variables	Number of medical investigations Mean±SD	Min–Max
Consultation	2.25±0.84	1–4
Intraocular pressure	2.76±1.40	0–9
Fundus examination	1.59±0.80	1–4
Visual field	0.73±0.52	1–3
Gonioscopy	0.32±0.20	0–2
Variables	Cost (Euros) Mean±SD	Min–Max
Consultation	35.67±10.36	7.62±68.60
Tonometry	31.70±10.06	2.28±64.02
Fundus examination	26.06±11.12	3.81±91.46
Visual field	34.75±16.77	19.05±91.46
Gonioscopy	19.81±11.73	6.86±30.49
Optical coherence tomography	32.47±7.16	27.44±45.73
Drugs	284.16±115.25	113.42±552.47
Medical direct cost	464.81±155.65	186.59±837.55
Non-medical direct cost	4.57±2.74	0.30±60.97
Total direct cost	468.47±155.34	187.51±845.17

SD: Standard deviation

The annual direct medical cost for the study population was estimated at 468.47 ± 155.34 Euros, with extremes of 187.51 and 845.17 Euros during the study year. The greatest proportion of out-of-pocket expenses (61.13% of medical costs) concerned the purchase of drugs, for an average cost of 284.16 ± 115.25 Euros, with extremes of 113.42 and 552.47 Euros.

[Table 4] shows the annual direct cost according to certain sociodemographic characteristics.

Table 4: Direct costs according to the sociodemographic profile and the severity of glaucoma.

Variables	Mean±SD (Euros)	P-value
Direct cost according to sociodemographic profile
Health-care facilities
Public sector	425.78±38.49	0.001
Private sector	562.22±139.18
Residency town
Yaounde	462.83±147.87	0.61
Other	473.04±54.88
Health insurance
Yes	498.35±154.88	0.26
No	442.10±155.19
Direct cost according to glaucoma severity
Severe glaucoma
Yes	534.17±150.77	0.06
No	469.23±91.46
Moderate glaucoma
Yes	466.18±108.23	0.9
No	457.80±146.35
Low glaucoma
Yes	434.63±141.77	0.1
No	484.32±159

SD: Standard deviation

Patients treated in the public sector spent an average of 425.78 ± 38.49 Euros, while those treated privately spent 562.22 ± 139.18 Euros during the study year, with a statistically significant difference (P = 0.001). Patients living in Yaounde spent a total of 462.83 ± 147.87 Euros over the year. Patients with private health insurance spent an average of 498.35 ± 154.88 Euros.

Analysis of the barriers to optimal glaucoma care shows that the main barrier was insufficient income as reported by sixty (48.17%) participants [Figure 2].

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Figure 2:

Distribution of the study population according to barriers to optimal glaucoma management.

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DISCUSSION

This study assessed the direct cost of managing POAG and identified obstacles to optimal management. Glaucoma is the 2^nd leading cause of blindness after cataracts in Africa, with the primary open-angle form being the most common.^[11,12] According to the literature, its prevalence is estimated at 4.16% in sub-Saharan Africa.^[11]

In the present study, more than 60% of participants were aged above 60 years. That can explain the proportion of severe glaucoma and comorbidity among the study population. Some systemic risk factors of glaucoma were present in the study population, namely, male gender (59.9%) and arterial hypertension (24.7%). According to the literature, ocular and systemic risk factors for this condition as age, gender, and vascular diseases have been identified in MelanoDerm populations.^[13]

In the present study, the severe form of glaucoma was the most frequent (more than 50%) and the average cup-to-disc ratio was 0.8 and 0.9 in the right and left eyes, respectively. Actually, POAG is frequently detected late and leads to blindness in African settings.^[2,11] Omgbwa et al. reported bilateral and unilateral blindness rates of 19.7% and 14.1%, respectively, among 1927 cases of blindness.^[12] Ellong et al. found a prevalence of bilateral and monocular blindness due to glaucoma of 8% (n = 108) and 32.9% (n = 441), respectively, in glaucoma patients in a sample of 24,462 records collected.^[2]

In the present study, 67.7% of participants had a higher level of education. Socioeconomic factors and awareness are key elements involved in the progression of glaucoma and the onset of blindness in MelanoDerm glaucoma patients. Lifelong follow-up is an integral part of glaucoma management, and failure to provide adequate follow-up can have serious consequences for patients.^[14]

Participants had performed between 1 and 4 consultations/ year. In addition, an average of two fundus examinations was performed over the year. In terms of explorations, participants performed less than one gonioscopic examination and less than one visual field examination during the year. The gonioscopic examination was not performed systematically. Examination of the optic nerve head is an important element in the diagnosis of glaucoma. According to Kyari et al., in a study of 250 ophthalmologists in Nigeria, optic disc examination in favor of glaucoma was the trigger for glaucoma management in 85% of cases. Moreover, a gonioscopic examination was performed in only 56% of cases.^[15]

The yearly average direct cost of medical care was 468.47 ± 155.34 Euros, equivalent to a monthly budget of 39.04 ± 12.94 Euros. The global direct cost reported in the present study was higher compared to that reported by Vonor et al. (277.69 ± 132.42 Euros).^[16] The average direct cost of glaucoma care was statistically higher in the private sector than in the public sector (P = 0.001). However, health coverage and type of glaucoma did not influence the direct cost of treatment. Medical treatment accounted for the highest proportion of the total direct cost of glaucoma, at over 60%. Monotherapy was the most common form of treatment, with prostaglandin agonists the most widely used molecules. However, prostaglandin agonists, which are increasingly preferred in the medical treatment of glaucoma for their efficacy, are more expensive than beta-blockers. In the present study, the monthly cost of medical treatment was 23.68 ± 9.6 Euros. This cost is above the average monthly costs reported by Sounouvou et al., in Benin^[7] and Bello, in Nigeria^[17] which were 17.8 ± 10.8 Euros and 21.3 Dollars (= 19.74 Euros), respectively. This could explain the difficulty of adherence to medical treatment in Africa^[18,19] and more particularly in Cameroon. Over 40% of participants in the present study reported a monthly income of <228 Euros and 68.8% had no health insurance or universal health coverage. Thus, the economic burden of glaucoma care is on the individual or his/her relatives. Our results are superimposed on those of Sounouvou et al. in Benin, who found that financial responsibility was assumed by the patient in 72% of cases due to a lack of health coverage.^[7] Universal health coverage is the ideal solution for the management of glaucoma, as it is a lifelong disease. Moreover, as 58.19% of patients are more than 60 years old, they are in the age group associated with more comorbidity that increases the economic burden.^[17]

The main obstacle to glaucoma care was insufficient finance, as reported by more than half of the participants. One of the major reasons for poor follow-up in glaucoma management in Africa is financial; this is due to the high cost of care^[19] and the lack of financial resources for the patients.^[18] The second barrier to appropriate management reported by participants is forgetfulness. Glaucoma management is a chronic pathology with high morbidity requiring regular awareness-raising to improve patient support and, above all, adherence to treatment. As such, it requires the strong involvement of the entire healthcare system in communication, screening, management, and active follow-up of patients.^[13] This would help preserve patients’ vision over the long term.

Potential limits of this study include the fact that we did not assess the household income of each participant. Moreover, in the case of source funding, the details of the family support instead of personnel one are not detailed. However, the present study, as the first one on the cost of glaucoma care in Cameroon, highlights the need for the involvement of all stakeholders to better manage glaucoma in our context.

CONCLUSION

The present study shows that the majority of participants finance their glaucoma management. The total direct cost of medical care during the year was 469.16 ± 155.5 Euros, of which 284.58 ± 115.4 Euros were devoted to anti-glaucoma drugs. The main barrier to optimal glaucoma care was the lack of financial resources. Cameroonians cannot afford to self-fund their glaucoma care in the long term. The introduction of universal health coverage for all and the strengthening of health systems would contribute to improving the management of this disease.