Table 5. Causes of ambulatory medical care utilization in patients with systemic lupus erythematosus and controls during the period 0.5 to 2 years preceding the index date.
| Diagnosis (ICD-9-CM code) | Group, mean ±SD | P | ||
| Patients with SLE | Controls | |||
| n = 337 | n = 1,348 | |||
| Diseases of the respiratory system (460–519) | 7.24±9.70 | 3.66±7.20 | <0.001 | |
| Acute respiratory infections (460–466) | 5.78±7.06 | 3.09±6.35 | <0.001 | |
| Other diseases of the upper respiratory tract (470–478) | 0.67±2.09 | 0.31±1.52 | <0.001 | |
| Pneumonia and influenza (480–488) | 0.36±2.34 | 0.14±0.78 | <0.001 | |
| Chronic obstructive pulmonary disease and allied conditions (490–496) | 0.37±1.09 | 0.09±0.84 | <0.001 | |
| Pleurisy (511) | 0.02±0.20 | 0.00±0.02 | 0.010 | |
| Pneumonitis (515–517) | 0 | 0 | NA | |
| Diseases of the digestive system (520–579) | 5.78±6.99 | 2.66±5.03 | <0.001 | |
| Disease of oral cavity, salivary glands and jaws (520–529) | 3.26±3.49 | 1.60±3.35 | <0.001 | |
| Disease of esophagus, stomach, and duodenum (530–537) | 1.20±3.22 | 0.54±2.50 | <0.001 | |
| Noninfectious enteritis and colitis (555–558) | 0.52±1.42 | 0.22±0.85 | <0.001 | |
| Other diseases of intestines and peritoneum (560–569) | 0.33±1.17 | 0.22±1.94 | <0.001 | |
| Liver diseases (570–573) | 0.36±1.67 | 0.06±0.46 | <0.001 | |
| Diseases of gall bladder/biliary tract/pancreas (574–577) | 0.10±0.08 | 0.01±0.22 | <0.001 | |
| Diseases of the musculoskeletal system and connective tissue (710–739) * | 4.35±7.48 | 1.22±4.21 | <0.001 | |
| Athropathies (711–719) | 1.87±4.45 | 0.33±1.84 | <0.001 | |
| Spine disorders (720–724) | 0.73±2.16 | 0.49±2.10 | <0.001 | |
| Disorder of tendon, brusa, muscle and fascia (725–729) | 1.08±2.63 | 0.36±1.57 | <0.001 | |
| Osteopathies and chondropathies (730–733) | 0.15±1.11 | 0.02±0.19 | <0.001 | |
| Diseases of the skin and subcutaneous tissue (680–709) | 3.89±5.90 | 0.91±2.84 | <0.001 | |
| Infection of skin and subcutaneous tissue (680–686) | 0.51±1.67 | 0.09±0.66 | <0.001 | |
| Inflammatory conditions of skin and subcutaneous tissue (690–698) | 2.24±4.21 | 0.41±1.70 | <0.001 | |
| Other diseases of skin and subcutaneous tissue (700–709) | 1.15±2.35 | 0.40±1.73 | <0.001 | |
| Disorders of the eye and adnexa (360–379) | 2.01±3.38 | 0.68±2.46 | <0.001 | |
| Diseases of female genital organ (610–629) † | 1.93±4.45 | 1.11±3.39 | 0.001 | |
| Diseases of the circulatory system (390–459) | 1.68±5.37 | 0.63±3.09 | <0.001 | |
| Diseases of the blood and blood-forming organs (280–289) | 1.22±4.61 | 0.04±0.53 | <0.001 | |
| Endocrine, nutritional and metabolic diseases, and immunity disorders (240–279) | 1.22±3.78 | 0.45±2.51 | <0.001 | |
| Infectious and parasitic diseases (001–139) | 0.99±2.56 | 0.37±1.71 | 0.001 | |
| Diseases of kidney (580–589) | 0.82±3.82 | 0.08±1.47 | <0.001 | |
| Mental disorders (290–319) | 0.80±3.13 | 0.37±2.67 | <0.001 | |
| Diseases of urinary system (590–599) | 0.59±2.18 | 0.21±1.06 | <0.001 | |
| Neoplasms (140–239) | 0.55±2.95 | 0.26±1.79 | <0.001 | |
| Diseases of the nervous system (320–359) | 0.53±2.20 | 0.13±0.97 | <0.001 | |
| Diseases of the ear and mastoid process (380–389) | 0.22±0.76 | 0.19±1.11 | <0.001 | |
| Complications of pregnancy, child birth, and the puerperium (630–679) † | 0.17±1.02 | 0.11±0.80 | 0.497 | |
| Diseases of male genital organ (600–608) ‡ | 0.09±0.45 | 0.13±0.99 | 0.497 | |
| Number of organ system involved § | ||||
| 1 | 3 (0.9) | 49 (3.6) | 0.007 | |
| 2 | 9 (2.7) | 88 (6.5) | 0.010 | |
| ≥3 | 324 (96.1) | 595 (44.1) | <0.001 | |
*Excluding the ICD-9-CM code 710.0.
†
Female only (patients with SLE, n = 293; controls, n = 1,172).
‡
Male only (patients with SLE, n = 44; controls, n = 176).
SD, standard deviation; SLE, systemic lupus erythematosus; NA, not applicable.
§
Represented as number (%).