JOURNAL OF THE LOUISIANA STATE MEDICAL SOCIETY
found on peripheral neurons and their myelin sheaths. The resulting autoimmune response is thought to be responsible for the presentation of GBS. Population and Methods
Surveillance System (NEDDS) Base System (NBS). IDRIS records confirmed, probable, and suspect cases of reportable diseases among Louisiana residents. Cases of campylobacteriosis, a reportable condition in the Louisiana Sanitary Code, were extracted from IDRIS for years 1999-2014.
The Louisiana Hospital Inpatient Discharge Database Data
Analysis
Data for this study was abstracted from the Louisiana Hospital Inpatient Discharge Database (LAHIDD). GBS hospitalizations were identified using the ICD-9 code indicative of GBS diagnoses, regardless of whether this was coded for in the Main Diagnosis or one of the eight secondary diagnoses. The ICD-9 code used for a GBS diagnosis is 357.0 – Acute Infective Polyneuritis. Concurrent diagnoses of infections were identified using ICD-9 codes between 001 and 139.8 which includes all diagnoses indicative of infection with a pathogenic organism. Concurrent diagnoses of pneumonia were identified in a similar manner using ICD-9 codes between 480 and 491.9 which includes all acute respiratory conditions. Concurrent diagnoses of additional neurologic conditions were identified using ICD-9 codes between 320 and 324.9 which include all diagnoses of meningitis, encephalitis, myelitis, and intracranial abscess, as well as ICD-9 codes between 349 and 357.9, excluding 357,which include all other diagnoses of disorders of the peripheral nervous system.
Trends in incidence rates were analyzed using the Cochran- Armitage chi-square test for trend. The Tukey Procedure was used for multiple pairwise comparisons of rates between age groups. Comparisons between genders and races were completed using the stratified Mantel-Haenszel chi-square test. Rates of increase were compared using a two-sample student’s t-test. All chi-square tests and pairwise comparisons were conducted using WinPEPI ver. 11.65. Two sample t-tests were performed using Microsoft Excel 2016.
RESULTS
General Trend
Figure 1 shows the GBS hospitalized case counts and rates per 100,000 population during the study period, from 1999-2014. The annual case count ranges from 142-255 with a mean of 211.8 ± 31.1. The annual hospitalization rates ranged from 3.2 to 5.6 per 100,000 population with a mean of 4.7 ± 0.6 and show a statistically significant positive trend (Cochran-Armitage chi- square test for trend = 46.28, p = 0.000) with an annual rate of increase of 2.87%, 95% CI: 1.39% - 4.38%.
Louisiana Infectious Disease Reporting Information System (IDRIS)
IDRIS is a customized version of a National Electronic Disease
Figure 1: GBS Hospitalizations and Rate per 100,000 Population in Louisiana from 1999-2014.
hospitalizations per 100,000 population for 0-1) and the very old (15.2 ± 3.6 hospitalizations per 100,000 population for the 65+ age group). There is a strong positive trend across age groups (Cochran-Armitage chi-square test for trend = 122.34, p = 0.000) with substantial increases beginning with the 15-19 age group. Multiple pairwise comparisons indicate a statistically significant
Rates by Age
Figure 2 shows the age-group distribution of GBS hospitalization rates per 100,000 population during the study period. GBS hospitalization rates per 100,000 population increase with age and vary greatly between the very young (mean = 0.4 ± 0.9
108 La State Med Soc VOL 170 JULY/AUG 2018
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