| Literature DB >> 27386383 |
Francis Bbosa1, Ronald Wesonga2, Peter Jehopio1.
Abstract
In this study, we identified predictors of malaria, developed data mining, statistically enhanced rule-based classification to diagnose malaria and developed an automated system to incorporate the rules and statistical models. The aim of the study was to develop a statistical prototype to perform clinical diagnosis of malaria given its adverse effects on the overall healthcare, yet its treatment remains very expensive for the majority of the patients to afford. Model validation was performed using records from two hospitals (training and predictive datasets) to evaluate system sensitivity, specificity and accuracy. The overall sensitivity of the rule-based classification obtained from the predictive dataset was 70 % [68-74; 95 % CI] with a specificity of 58 % [54-66; 95 % CI]. The values for both sensitivity and specificity varied by age, generally showing better performance for the data mining classification rules for the adult patients. In summary, the proposed system of data mining classification rules provides better performance for persons aged at least 18 years. However, with further modelling, this system of classification rules can provide better sensitivity, specificity and accuracy levels. In conclusion, using the system provides a preliminary test before confirmatory diagnosis is conducted in laboratories.Entities:
Keywords: Malaria diagnosis; Rule-based classification; Sensitivity; Specificity; Statistics
Year: 2016 PMID: 27386383 PMCID: PMC4929097 DOI: 10.1186/s40064-016-2628-0
Source DB: PubMed Journal: Springerplus ISSN: 2193-1801
Malaria prevalence, signs and symptoms by hospital
| Malaria | Kalisizo Hospital | Kisubi Hospital | Overall |
|---|---|---|---|
| Percentage (%) | Percentage (%) | Percentage (%) | |
| Proportion with malaria | 12.3 | 76.2 | 22.2 |
|
| |||
| Febrile | 98.2 | 53.0 | 91.2 |
| Fever | 79.7 | 20.5 | 70.5 |
| Rigors | 94.8 | 78.8 | 92.3 |
| Drowsy | 94.3 | 57.0 | 88.5 |
| Fits | 99.9 | 91.4 | 98.6 |
| Dark urine | 98.9 | 97.4 | 98.7 |
| Joint pains | 93.2 | 90.7 | 92.8 |
| Vomit | 96.4 | 63.6 | 91.3 |
| Jaundice | 100.0 | 91.4 | 98.7 |
| Splenomegaly | 97.7 | 73.5 | 93.9 |
| Total | 822 | 151 | 973 |
Malaria signs and symptoms by diagnosis
| Signs and symptoms | Malaria diagnosis | ||
|---|---|---|---|
| Negative percentage (%) | Positive percentage (%) | Total percentage (%) | |
| Febrile | 97.5 | 69.0 | 91.2 |
| Fever | 78.2 | 43.5 | 70.5 |
| Rigors | 94.9 | 83.3 | 92.3 |
| Drowsy | 93.7 | 70.4 | 88.5 |
| Fits | 99.7 | 94.4 | 98.6 |
| Dark urine | 98.7 | 98.6 | 98.7 |
| Joint Pains | 92.9 | 92.6 | 92.8 |
| Vomit | 95.2 | 77.3 | 91.3 |
| Jaundice | 99.7 | 94.9 | 98.7 |
| Splenomegaly | 97.5 | 81.5 | 93.9 |
| Total | 757 | 216 | 973 |
Fig. 1Clinical diagnosis algorithm
Fig. 2Input output diagnosis for malaria based on signs and symptoms
Fig. 3Patient rule-based online interface
Fig. 4Malaria diagnosis data mining and classification rules
Malaria rule based diagnosis and classification against the symptoms and signs
| Symptoms and signs | Age category | |||||
|---|---|---|---|---|---|---|
| Adults | Teens | Children | ||||
| Rule 1 | Rule 2 | Rule 3 | Rule 4 | Rule 5 | Rule 6 | |
| Febricity | Yes | – | – | – | – | Yes |
| Drowsiness | – | Yes | Yes | – | – | Yes |
| Fever | – | Yes | – | – | – | Yes |
| Dark urine | – | Yes | – | – | – | – |
| Rigors | – | Yes | – | – | – | Yes |
| Joint pains | – | Yes | – | – | Yes | – |
| Vomiting | Yes | – | Yes | Yes | – | – |
| Splenomegaly | – | – | – | Yes | Yes | – |
| Malaria outcome | POS | POS | POS | POS | POS | POS |
POS positive malaria outcome
Information in binary digits gained by branching on each attribute
| Symptom/sign | Information gain |
|---|---|
| Overall I (p,n) | 0.5380 |
| Age group | 0.0280 |
| Febricity | 0.0040 |
| Fever | 0.0010 |
| Rigors | 0.0005 |
| Drowzy | 0.0020 |
| Darkurine | 0.0010 |
| Joint pains | 0.0000 |
| Vomit | 0.0030 |
| Splenomegaly | 0.0130 |
Predicted number of patients using rule-based classification against true clinical diagnosis by age
| Predicted malarial status | True clinical diagnosis of malaria | |||||||
|---|---|---|---|---|---|---|---|---|
| 5–9 Years | 10–17 Years | 18 Years and above | Total | |||||
| Positive | Negative | Positive | Negative | Positive | Negative | Positive | Negative | |
|
| ||||||||
| Positive | 6 | 4 | 10 | 3 | 65 | 8 | 81 | 15 |
| Negative | 5 | 4 | 4 | 3 | 25 | 14 | 34 | 21 |
| Total | 11 | 8 | 14 | 6 | 90 | 22 | 115 | 36 |
|
| ||||||||
| Positive | 56 | 22 | 20 | 19 | 11 | 15 | 90 | 16 |
| Negative | 5 | 270 | 5 | 105 | 4 | 290 | 11 | 705 |
| Total | 61 | 292 | 25 | 124 | 15 | 305 | 101 | 721 |
Goodness of fit for rule-based classification of patients’ malaria outcome by age
| Goodness of fit statistics | 5–9 Years | 10–17 Years | 18 Years and above | Total | ||||
|---|---|---|---|---|---|---|---|---|
| % | 95 % CI | % | 95 % CI | % | 95 % CI | % | 95 % CI | |
|
| ||||||||
| Sensitivity | 0.55 | [0.43–0.66] | 0.71 | [0.62–0.80] | 0.72 | [0.69–0.76] | 0.70 | [0.68–0.74] |
| Specificity | 0.50 | [0.35–0.67] | 0.50 | [0.36–0.70] | 0.64 | [0.58–0.73] | 0.58 | [0.54–0.66] |
| Positive predictive value | 0.60 | [0.46–0.77] | 0.77 | [0.67–0.91] | 0.89 | [0.87–0.93] | 0.84 | [0.82–0.89] |
| Negative predictive value | 0.44 | [0.30–0.62] | 0.43 | [0.30–0.63] | 0.36 | [0.31–0.45] | 0.38 | [0.34–0.46] |
|
| ||||||||
| Sensitivity | 0.92 | [0.90–0.93] | 0.80 | [0.74–0.83] | 0.73 | [0.63–0.76] | 0.89 | [0.87–0.90] |
| Specificity | 0.92 | [0.91–0.93] | 0.85 | [0.79–0.87] | 0.95 | [0.93–0.96] | 0.98 | [0.97–0.98] |
| Positive predictive value | 0.72 | [0.67–0.74] | 0.51 | [0.41–0.56] | 0.42 | [0.30–0.45] | 0.85 | [0.82–0.86] |
| Negative predictive value | 0.98 | [0.98–0.98] | 0.95 | [0.94–0.96] | 0.99 | [0.98–0.99] | 0.98 | [0.98–0.99] |
Quality of the classification rule evaluation for Kisubi Hospital (n = 151)
| Age group | Adults (18+ years) | Teens (10–17 years) | Children (5–9 years) | |||
|---|---|---|---|---|---|---|
| Coverage by age group (%) | 74.20 | 13.30 | 12.50 | |||
| RULE | RULE (1) | RULE (2) | RULE (3) | RULE (4) | RULE (5) | RULE (6) |
| Coverage (%) | 17.90 | 0.00 | 15.00 | 21.10 | 5.30 | 0.00 |
| Accuracy (%) | 85.00 | 0.00 | 66.70 | 75.00 | 100.00 | 0.00 |
| Sample (n) | 112 | 20 | 19 | |||