The prevalence of LTOT was significantly higher in those eight counties
where GPs took part in LTOT prescribing, compared with the rest of the
counties: 34.4 per 100,000 vs 19.2 per 100,000 (p < 0.001).
Generally, if GPs had initiated LTOT, the patients were older, more
often male, more often prescribed oxygen as needed or < 15 h/d, more
often using oxygen < 15 h/d, more seldom delivered a concentrator and
a mobile system, had more seldom detected hypoxemia, and were
prescribed a higher oxygen flow (Tables 4, 5
). Incorrect prescriptions of LTOT by GPs were, however, not able to
explain all the geographic differences. For instance, in one county,
where only hospital doctors were prescribing LTOT, 41% of the patients
were current smokers and hypoxemia was only documented in 34% of the
patients who started after May 1993. In a univariate analysis, female
patients were more often compliant with guidelines than male patients:
39% vs 28% (p = 0.015). However, when a multiple regression
analysis was employed to determine whether gender and the type of
doctor (chest specialist, internist, or GP) had an impact on compliance
with guidelines, the influence of gender was no longer significant.
When GPs and male gender were set as reference, the odd ratios (95%
confidence intervals) for good compliance were as follows: female
gender, 1.4 (1.0 to 2.1); internist, 1.6 (0.9 to 2.9); chest specialist
at nonpulmonary department, 2.1 (1.1 to 3.9); and chest
specialist at pulmonary department, 5.3 (2.9 to 9.1).