Treatment of hip/knee osteoarthritis in Dutch general practice and physical therapy practice: an observational study

In this study, we described the content of care registered in electronic records of
12.118 patients with hip/knee OA visiting their GP and/or physical therapist during
2006 to 2011, including the compliance to the SCS.

A remarkable result of our study comprised a lower prescription rate of pain medication
(NSAIDs and acetaminophen) in patients with hip/knee OA in comparison to previous
studies 14]; Belo J, Berger M, Koes B, Bierma Zeinstra SM (unpublished work). The lower use of
acetaminophen and NSAIDs might be explained by the increasing availability of those
(low-dosed) drugs over the counter. As a consequence, the total use of NSAIDs and
analgesics in the OA population is probably underestimated in this study.

In line with the SCS, in Dutch general practice less advanced treatment modalities
are generally more often applied than more advanced treatment modalities. However,
only a small minority of patients is treated by a combination of different interventions
belonging to one step before turning to the next step, within the time frame of our
study. Most deviations from the SCS concern GPs’ prescriptions and their referral
policy. With respect to GPs’ prescribed pain medication, our results show that NSAIDs
(especially Diclophenac (combinations), Ibuprofen, Meloxicam and Naproxen) and tramadol
(step-2 interventions) are more often prescribed than analgesics (step-1 intervention).
This prescription behaviour has previously been indicated in an observational study
by Cardol et al. 14]. Moreover, a more recent study investigating GPs’ attitudes regarding SCS recommendations,
showed that 21% of the GPs (strongly) agree with the statement ‘NSAIDs should be the first choice of pain medication in patients with OA’15]. Given the recognized increased risk of several adverse outcomes in older adults
due to the frequent use of NSAIDs and to improve guideline adherence, GPs could be
advised to optimize the analgesics policy prior to consider NSAIDs prescription in
patients with hip/knee OA 16]. Besides the prescription policy, deviations from the SCS are found regarding GPs’
referrals as well. In the NPCD, GPs registered fewer referrals to allied health care
providers (exercise therapy, dietary therapy (step-2) than to orthopaedic surgeons
(step-3). Partially, this could be explained by the moderate quality of the referral-registration
in the medical records and the introduction of patient self-referral for allied health
care. However, previous work, which has been published prior to the introduction of
direct access of allied health care, also showed a lower referral rate for physical
therapy compared to orthopaedic surgery 14]. Therefore, the question arises whether GPs could improve care by first ensuring
optimal non-surgical care in primary care setting has been delivered, before referring
to secondary care 17]. Fortunately, recent (unpublished) research in a population in which the SCS has
been implemented showed that patients who are referred to secondary care are significantly
more extensively treated by non-surgical interventions in primary care compared to
patients who were not referred to secondary care (Barten JA, Smink AJ, Swinkels ICS,
et al.)

The introduction of direct access to allied health care for example aimed to achieve
a rearrangement of health care organization. Translated to OA care, it could have
been expected that non-pharmacological step-1 interventions had been integrated in
physical therapists’ treatment in case of patient self-referral. However, we did not
indicate a difference with respect to the application of ‘information and advice’
between GP-referred and self-referred patients in physical therapy practice. Besides,
only a handful of patients exclusively received education. The rearrangement of care,
hence, seems to be in its infancy. It should be remarked that almost half of the patients
using self-referral presented recurrent complaints (46%). These patients might have
been treated by a step-1 intervention by a physical therapist or their GP, prior to
the timeframe of this study. Further research is recommended to able an evaluation
of the effects of task-shifting in OA-care.

As already mentioned, self-referred patients with hip/knee OA often present recurrent
complaints in physical therapy practice. In accordance with studies in the general
population and in patients with low back pain, the recurrence rate in self-referred
patients significantly exceeds the recurrence rate in GP-referred patients 18], 19]. Patients with recurrent complaints might be more aware of direct accessibility and,
therefore, are more likely to omit their GP in case of recognizable musculoskeletal
complaints. This rationale is confirmed by research of Leemrijse et al. 18], indicating that the use of direct access was significantly higher in patients who
received earlier treatment by a physical therapist.

Another difference between self-referred and GP-referred patients concerned the less
frequent application of activities-related exercise therapy in self-referred patients.
Commonly, treatment starts with improving impairments of body functions and gradually
shifts to diminishing limitations in activities of daily life. At the same time, the
role of the physical therapist changes from ‘hands-on therapist’ to ‘coach’ and the
frequency of treatment sessions decreases. Possibly, this gradual phase out is less
often used in patients who refers themselves. Physical therapists might focus on improving
impairments, leaving the translation to activities of daily life to patients themselves.
This situation stands to reason since a sizeable proportion of the self-referred patients
has already gained some experience in the translation to daily life: recurrence rates
are high. Furthermore, the lower amount of care in self-referred patients seems to
support this rationale.

This study has some limitations. Firstly, in the NPCD, treatment episodes in general
practice are constructed retrospectively. As a consequence, applied interventions
(consults, prescriptions and referrals) were related to a treatment episode due to
OA, unless they were aimed at treating any comorbidity. Secondly, both the increasing
use of direct-access and the moderate registration of referrals in the medical record
could have induced an underestimation of referrals to other health professionals,
including physical therapy and dietary therapy. Since exercise therapy and encouraging
weight loss are key recommendations in clinical guidelines for the treatment of lower
limb OA 5], a higher referral rate than the indicated 5% respectively 1% could have been expected.
Thirdly, we did not take into account the hierarchical structure of the data with
patients nested in health professionals, nested in primary care practices both in
general practice as well as in physical therapy practice. However, previous work showed
that variances in health care use in patients with hip/knee OA were mainly located
at patients’ level 20]. Fourthly, we were not able to evaluate thoroughly the sequence of the applied interventions
in general practice, but evaluated which interventions from each step were applied
in patients with hip/knee OA. Furthermore, we did not take into account whether a
patient’s treatment was evaluated during an evaluation visit before turning to the
next step, which is described as an integral part of the SCS 21]. Finally, data were extracted from two voluntary-based, separate registrations, both
part of the NPCD. Selection bias could be excluded, as the number of patients objecting
to participate in the NPCD is negligible and participating practices reflects the
reality of Dutch general practices. As the NPCD comprises several, separate registrations,
patients referred for physical therapy were not necessarily represented in the GP
data and vice versa, disabling an evaluation of the compliance to the SCS in a singular
patient by combining electronic data derived from several health professionals. At
this moment, the NPCD is prepared to enable integration of data from several health
professionals belonging to a singular patient. This opens the way to evaluate the
compliance to the SCS more thoroughly, including the effects of using direct accessibility
of allied health care on both patient-outcomes and the process of care.