The Clinical Presentation and Factors Associated with Disease Severity of Rheumatoid Arthritis in Uganda: A Cross-Sectional Study

Figures & data

Table 1 Socio-Demographic Characteristics of the Study Participants

Characteristic	Frequency (n=170)	Percentage (%)
Gender
Female	138	81.2
Age (years)
<30	31	18.2
30–50	80	47.1
>50	59	34.7
Duration of rheumatoid arthritis at study recruitment
<5 years	95	56
≥5 years	75	44
Chronic illness (n=96)
Hypertension	38	39.6
Diabetes	20	20.8
Diabetes and hypertension	4	4.2
Human immunodeficiency virus seropositive	4	4.2
Other chronic illnesses*	30	31.2
Current medication (n=166)
Non-steroidal anti-inflammatory drugs	147	94
Folic acid	86	52
Steroids (oral prednisolone)	134	81
Anti-hypertensive	40	24
Anti-diabetics	8	4.8
On conventional drugs	118	69
Methotrexate	81	69
Hydroxychloroquine	59	50
Leflunomide	3	2.5
Sulfasalazine	2	1.7
Rituximab	3	2.5
Body mass index (kg/m^2)
<18.5	8	4.7
18.5–24.9	97	57.1
≥25.0	65	38.2
DAS28-ESR, mean±SD: 5.7±1.6
DAS28-ESR
Remission	7	4.1
Low	7	4.1
Moderate	45	26.5
High	111	65.3
Functional disability/MHAQ score, median (IQR): 0.5 (0.13–1.62)
Functional disability score
≤0.5	87	51
>0.5	83	49

Notes: ^*Other chronic illnesses included sickle cell disease (3.1%), pulmonary tuberculosis (2.1%), varicose veins (1.0%), hypothyroidism (1.0%) and epilepsy (1.0%).

Abbreviations: DAS28-ESR, Disease Activity Score based on 28-joint count with erythrocyte sedimentation rate; SD, standard deviation; MHAQ, Modified Health Assessment Questionnaire; IQR, interquartile range.

Table 2 Laboratory Characteristics of the Study Participants

Characteristic	Frequency (n)	Percentage (%)
Rheumatoid factor (IU/mL) (N=164)
Positive	147	89.6
Erythrocyte sedimentation rate (mm/h)
Elevated	150	88.2
C-reactive protein (mg/dL) (N=77)
Elevated	71	92.2
Anti-cyclic citrullinated peptide (IU/mL) (N=159)
Elevated	139	87.4
Platelet count (cells/L) (N=158)
Low (<150)	4	2.5
Normal (150–450)	138	87.3
Elevated (>450)	16	10.1
Hemoglobin level (g/dL)
Normal (male: >13, female: >12)	106	62.4
Mild anemia (male: 11–13, female: 11–12)	31	18.2
Moderate anemia (8–<11)	31	18.2
Severe anemia (< 8)	2	1.2

Table 3 Clinical Characteristics of Rheumatoid Arthritis by Joint Involvement

Symptoms	Pain, n (%)	Swelling, n (%)
PIPs	116 (68.2)	82 (48.2)
MCPs	133 (78.2)	105 (61.8)
Wrist	135 (79.4)	117 (68.8)
Elbow	73 (42.9)	33 (19.4)
Shoulder	90 (52.9)	42 (24.7)
Knee	117 (68.8)	84 (49.7)
All	23 (13.5)	58 (34.1)
PIP + MCP	115 (67.7)	79 (46.5)
PIP + MCP + wrist	106 (62.4)	72 (42.4)
Shoulder + knee + elbow	63 (37.1)	24 (14.1)

Abbreviations: PIP, proximal interphalangeal joint; MCP, metacarpophalangeal joint.

Figure 1 Disease Activity Scores based on 28-joint count and erythrocyte sedimentation rate (DAS28-ESR) among the study participants.

Table 4 Clinical and Laboratory Factors Associated with Disease Severity

Characteristic	Not Severe, n (%)	Severe, n (%)	OR (95% CI)	p-Value
Gender
Male	8 (25.0)	24 (75.0)	1	0.204
Female	51 (37.0)	87 (63.0)	0.6 (0.24–1.35)
Age (years)
<30	11 (35.5)	20 (64.5)	1
30–50	25 (31.3)	55 (68.7)	1.2 (0.51–2.91)	0.669
>50	23 (39.0)	36 (61.0)	0.9 (0.34–2.12)	0.745
Smoking history
No	54 (34.8)	101 (65.2)	1
Yes	5 (33.3)	10 (66.7)	0.3 (0.2–3.9)	0.319
Duration of rheumatoid arthritis at study recruitment	59 (34.7)	111 (65.3)	11.1 (6.4–19.2)	<0.001
Other chronic illness
No	19 (25.7)	55 (74.3)	1
Yes	40 (41.7)	56 (58.3)	0.5 (0.2–0.9)	0.031
Body mass index (kg/m^2)
<18.5	4 (50.0)	4 (50.0)	1
18.5–24.9	27 (27.8)	70 (72.2)	2.3 (0.6–11.1)	0.199
≥25.0	28 (43.1)	37 (56.9)	1.3 (0.3–5.8)	0.71
Functional disability/MHAQ score	59 (34.7)	111 (65.3)	3.5 (2.4–5.0)	<0.001
Rheumatoid factor (IU/mL) (N=164)
Negative	9 (52.9)	8 (47.1)	1
Positive	48 (32.7)	99 (67.3)	2.3 (0.8–6.4)	0.103
Erythrocyte sedimentation rate (mm/h)
Normal	11 (55.0)	9 (45.0)	1
Elevated	48 (32.0)	102 (68.0)	2.6 (1.0–6.7)	0.048
C-reactive protein (mg/dL) (N=77)
Abnormal (>3)	23 (32.4)	48 (67.6)	1
Normal (≤3)	2 (33.3)	4 (66.7)	1.0 (0.1–5.6)	0.962
Anti-CCP (IU/mL) (N=159)
Normal (<7)	8 (40.0)	12 (60.0)	1
Elevated (≥7)	49 (35.3)	90 (64.7)	1.2 (0.5–3.0)	0.679
Platelet count (cells/L) (N=158)
Normal (150–450)	50 (36.2)	88 (63.8)	1
Elevated (>450)	5 (31.3)	11 (68.7)	0.8 (0.3–2.4)	0.694
Low (<150)	0 (0)	4 (100.0)	–	–
Hemoglobin level (g/dL)
Normal	39 (36.8)	67 (63.2)	1
Mild anemia	7 (22.6)	24 (77.4)	2.0 (0.78–5.1)	0.145
Moderate anemia	11 (35.5)	20 (64.5)	1.1 (0.45–2.4)	0.894
Severe anemia	2 (100.0)	0 (0)	–	–

Abbreviations: MHAQ, Modified Health Assessment Questionnaire; anti-CCP, anti-cyclic citrullinated peptide; OR, odds ratio; CI, confidence interval.

Table 5 Multivariable Logistic Analysis for Factors Associated with Disease Severity

Characteristic	Adjusted Odds Ratio	(95% CI)	p-Value
Gender
Male	1
Female	0.5	(0.1–2.5)	0.406
Educational level attained
None/primary	1
Secondary/tertiary	0.6	(0.2–1.8)	0.398
Smoking history
No	1
Yes	1.1	(0.1–7.5)	0.945
Duration of rheumatoid arthritis at study recruitment	0.9	(0.8–0.9)	0.004
Other chronic illness
No	1
Yes	0.4	(0.1–1.5)	0.165
Conventional medicine
No	1
Yes	1.3	(0.4–4.6)	0.675
Body mass index (kg/m^2)
<18.5	1	(0.7–109.3)	0.099
18.5–24.9	8.5	(0.3–48.2)	0.300
≥25.0	3.8
Functional disability/MHAQ score	1.7	(1.4–2.2)	<0.001
Rheumatoid factor (IU/mL) (n=164)
Negative	1
Positive	4.0	(0.7–22.0)	0.107
Anti-CCP (IU/mL) (n=159)
Normal (<7)	1
Elevated (≥7)	2.9	(0.5–16.0)	0.214
Platelet count (cells/L) (n=158)
Normal (150–450)	1
Elevated (>450)	0.4	(0.1–2.8)	0.394
Low (<150)	–	–	–
Hemoglobin level (g/dL)
Normal	1
Mild	1.5	(0.3–6.6)	0.568
Moderate	1.1	(0.2–4.1)	0.982
Severe	–	–	–

Abbreviations: MHAQ, Modified Health Assessment Questionnaire; anti-CCP, anti-cyclic citrullinated peptide; CI, confidence interval.