Five-year follow-up of an evidence-based prescribing intervention

AIMS AND METHOD

We studied the impact of an evidence-based multidisciplinaryintervention to reduce six sub-optimal aspects of psychotropicprescribing, combined as a Prescribing Practice Quality (PPQ)score over a 5-year follow-upperiodinacommunity mental healthservice.

RESULTS

Sub-optimal prescribing practices were significantly reducedafter 1 year and these improvements were sustained at 5-yearfollow-up. The PPQ scores were significantly reduced (P<0.001)in both the overall population attending at each follow-uppoint as well as in the ever-present population (n=163). Useof high-dose antipsychotics and thioridazine ceased entirely;use of sedative hypnotic agents was less amenable to reduction.

CLINICAL IMPLICATIONS

Multifaceted interventions can achieve sustained improvementsin prescribing practices in real-world settings.

Introduction

TOP

Introduction

Despite the drive to standardise clinical practice accordingto evidence-based guidelines, factors that relate to implementationin routine practice are not well-studied (Bauer, 2002). Disseminationof guidelines and simple educational interventions appear tohave limited impact. Practice change is more likely where itinvolves multifaceted approaches that target various resistance points and are supported by resource allocation, regular remindersand monitoring of practice (Dollman et al, 2005). Moreover,even where change occurs, less is known about sustaining improvements,with evidence indicating that short-term gains are difficultto maintain over time (Caswell et al, 2006).

Although information on the use of psychotropic agents is readily available, prescribing in real-world settings frequently deviatesfrom suggested guidelines and licensing arrangements (Harrington et al, 2002;Hodgson & Belgamwar, 2006; Spinewine et al, 2007). A recentreview by the Royal College of Psychiatrists (2007) highlightedthe lack of data regarding the frequency of unlicensed prescribing in UK services, but European studies indicate that up to 66%of out-patient antipsychotic prescriptions are for unlicensedindications. In part, this reflects the complexities of real-worldclinical practice where patient profiles often differ considerablyfrom those of efficacy studies. Combination strategies, forexample, benefit many patients with difficult-to-treat illness but remain insufficiently studied and not included within licensedindications (Karow & Lambert, 2003). However, other practicesare discouraged because of concerns over safety such as increasedrisk of accidents (Department of Health and Children, 2002)or cardiotoxicity (Reilly et al, 2000).

We have previously investigated factors associated with sixaspects of psychotropic prescribing (Meagher & Moran, 2003)and studied the impact of a multidisciplinary interventionon practices at 1-year (Moran et al, 2006) and 2-year (Raju & Meagher, 2005) follow-up. This work indicated that sub-optimal prescribingpractices (e.g. polypharmacy and use of maintenance benzodiazepines)was substantially reduced by an intervention involving clearguidelines for discontinuation, education, provision of alternativenon-pharmacological supports (e.g. anxiety management interventions)and regular monitoring of prescribing patterns. We further studiedprescribing practices as part of an annual prescribing audit5 years after the initial intervention to identify the extentto which improvements in prescribing were sustained at 5-yearfollow-up, the success in reducing individual sub-optimal practices,and factors associated with sustained improvement.

Method

TOP

Method

The study was conducted in the St Anne’s Community MentalHealth Service, which provides a general adult psychiatry servicefor a catchment area of approximately 50 000 persons in south-eastLimerick. We documented six aspects of sub-optimal psychotropicprescribing rated as present (1) or absent (0) to produce aPrescribing Practice Quality (PPQ) score (Box 1), with higherscores reflecting less optimal practice. Previous work identifyingdeterminants of sub-optimal prescribing and the impact of amultidisciplinary intervention on practice has described thePPQ (including item definitions) and the multicomponent interventionin detail (Meagher & Moran, 2003; Raju & Meagher, 2005; Moran et al, 2006).

In the period since the original intervention there has beencontinued emphasis on the agreed prescribing protocols, witha brief educational session for each new doctor as part ofservice induction. In addition, an annual audit allows monitoringof service contacts, ICD-10 diagnoses and prescribing practiceswithin the service, and allows feedback as to prescribing patterns as part of ongoing service review. Two specific aspects ofpractice were not considered ‘sub-optimal’ forthe purposes of this study because they reflected specificagreed practices in the service: the first was targeted polypharmacywith the combination of a serotonin – noradrenaline reuptakeinhibitor (either venlafaxine or duloxetine) with mirtazapinefor treatment-resistant depressive illness (Meagher et al, 2006; Hannon et al, 2007), and the second was short-term use ofquetiapine in low doses (25 - 100 mg) as a hypnotic agent.

Box 1. Prescribing Practice Quality (PPQ) items and scoring

Polypharmacy(i.e. use of two agents of same class)

Receiving thioridazine

High-doseantipsychotic use (total dose greater than 1000 mg/day in chlorpromazineequivalents)

Maintenance benzodiazepine treatment

Maintenancehypnotic treatment

Routine use of anticholinergic agent

Scoring:1 point per item present; range 0-6; higher scores indicateless optimal prescribing.

Statistical analysis was conducted using SPSS version 14 forWindows. The PPQ scores for total populations at each pointwere compared with Wilcoxon signed ranks testing. Independentt-tests were used to compare age and duration of service attendance.Chi-squared tests were used to compare the frequency of severemental illness, depot antipsychotic treatment and individualPPQ items between those ever-present in the service and those not.

Results

TOP

Results

Table 1 shows the demographic and clinical characteristicsof service attenders at initiation of the programme (in 2001),at 1-year follow-up (2002) and at 5-year follow-up (2006).The overall case-load, age, gender balance, duration of service attendance and percentage with severe mental illness were similarover the 5 years. Table 2 shows the frequency of sub-optimalprescribing practices (both overall and individual items) atthe three time points. There was a consistent reduction in meanPPQ score for the total population at each assessment pointas well as a reduction in the percentage of patients with atleast one sub-optimal aspect of their prescribed medications,from almost half in 2001 (46%) to just over a quarter in 2006(27%).

View this table:
[in this window]
[in a new window]

Table 1. Demographic and clinical characteristics (2001–2006)

View this table:
[in this window]
[in a new window]

Table 2. Sub-optimal prescribing practices (2001–2006)

Two aspects of prescribing - use of thioridazine, and high-dose antipsychotic treatment - ceased entirely over the course ofthe study. In contrast, the use of anticholinergic agents andbenzodiazepines declined during the initial phase of the study(2001-2) but remained relatively stable between 2002 and 2006,indicating that the initial reduction in use was sustainedover the longer period of follow-up. The specific hypnotic agents prescribed did alter, with relatively greater use of zopicloneover time: n=24 (23% of total hypnotic use) in 2001, n=24 (30%)in 2002 and n=30 (49%) in 2006.

A total of 163 patients were clients of the service at all threeevaluation points. These ‘ever-present’ patientswere older than the general population attending in 2006 (P<0.001),and were more likely to have severe mental illness (66% v.26%, P<0.001) and to be in receipt of depot antipsychotictreatment (18% v. 3%, P<0.001). The mean PPQ scores forthese patients are shown in Table 3. The percentage of patientsfrom this population who had at least one aspect of prescribingthat was sub-optimal (i.e. a PPQ score of 1 or more) diminishedover time from 46% in 2001 to 38% in 2002 and 33% in 2006.Mean PPQ scores were significantly reduced at 2002 v. 2001(P<0.001) and at 2006 v. both 2001 (P<0.001) and 2002(P<0.001).

View this table:
[in this window]
[in a new window]

Table 3. Prescribing Practice Quality scores for ‘ever-present’ patients (n=163)

The ever-present population was further subdivided into thosewho had maintained improved prescribing (n=58) and those whohad not (n=105) at 5-year follow-up. A greater likelihood ofbeing in the improved group was associated with higher baselinePPQ score: 0.2 (s.d.=0.5) v. 2.1 (s.d.=0.9), P<0.001. Therewere trends towards greater likelihood of having improved PPQscores in those with severe mental illness (P=0.09) and olderage (P=0.06). Improved PPQ score was not related to gender,duration of service attendance, treatment with depot antipsychoticmedication, frequency of attendance at services within the previousyear or receipt of multidisciplinary shared care (i.e. attendingat least two members of the multidisciplinary team).

Thirty-nine patients were receiving depot antipsychotic agentsat the 2006 review. These patients were significantly older(mean age 55.9 years, s.d.=12.4; P<0.001), had attendedthe service for longer (mean 15.9 years, s.d.=10.3; P<0.001)and had significantly higher PPQ scores (mean score 0.85, s.d.=0.78;P<0.001) than those not receiving depot antipsychotic medication.This reflected a high rate of anticholinergic use (52%) andconcomitant oral antipsychotic use (38%) in this population.

Discussion

TOP

Discussion

We report a 5-year follow-up of an evidence-based prescribingintervention in a real-world setting indicating that improvementsin prescribing quality can be maintained over time. Improvementswere evident both in the ongoing ‘ever-present’population as well as the total population attending the serviceat follow-up, indicating a reduction in sub-optimal practicesin both pre-existing cases and where new medication was initiated. These benefits were maintained by minimal formal intervention- an initial education session incorporated into the inductionprocess focusing on policies around sub-optimal practices supportedby emphasis of alternative strategies in day-to-day practice(e.g. multidisciplinary team meetings) and regular audit withfeedback at an annual service review. Our study indicates that change driven by the collaborative efforts of clinical staff,and therefore sensitive to the demands of everyday practicewithin that service (including local resource strengths andlimitations), produced sustained improvement in practice. Coerciveapproaches (e.g. mandatory prescribing restrictions) are effectivein changing practice (Wagner et al, 2007) but can be associatedwith increased subsequent polypharmacy, reduced treatment adherenceand greater in-patient and emergency service utilisation (Tamblyn et al, 2001;Parks & Surles, 2004; Soumerai, 2004). We did not findany increase in polypharmacy, and admission rates decreasedover the study period, suggesting that in-patient service use and non-compliance-related relapses were not a common consequence.The specific approach to benzodiazepine use in our programmeinvolved patient-controlled dose reduction (Raju & Meagher, 2005)emphasising the advantages of collaboration between patientsand clinical staff in delivering practice change.

Measuring the longer-term impact of interventions and identifying predictors of change is complicated by factors illustratedin this study. The only identified positive predictor of improvedprescribing practice at 5-year follow-up was baseline PPQ score.We previously identified exposure to adjunctive supportiveinputs (e.g. anxiety management) and chronicity of sub-optimalprescribing practice as predictors of improved prescribing at 1-year follow-up, but these factors were difficult to measureover more prolonged periods. It is interesting that patientsreceiving depot antipsychotic medications continued to haveless than optimal prescribing despite being previously highlightedfor particular attention (Meagher & Moran, 2003), reflectingthe tendency for use of anticholinergic agents and antipsychotic polypharmacy in this group. In addition, the PPQ was affectedby changing practices, with some of the original measures (e.g.use of thioridazine) now extremely uncommon and less usefulindicators of prescribing quality. Moreover, even though someaspects of prescribing are enduring indicators (polypharmacy,benzodiazepine use), the specific agents involved changed over time.

Where polypharmacy is driven by emerging evidence of efficacy,or as a means to reduce side-effects (e.g. clozapine augmentationwith atypical antipsychotics), it can reflect optimal practice.Moreover, polypharmacy may be driven by demonstrated benefitsfor individual patients even if efficacy studies are lacking.It may be that optimal patient outcomes require a low frequencyof practices that are generally considered sub-optimal but have demonstrable benefits for individual patients. Moreover, clinicalpractice is sometimes more advanced than standards identifiedby randomised controlled trials or that use specifically licensedby regulatory bodies. However, it is often the case that inreality much sub-optimal prescribing reflects educational deficitsor other constraints such as a lack of access to alternateinterventions for disabling problems (Stone et al, 2002) andoften occurs by default rather than design. This spectrum ofprescribing is highlighted in a recent report (Royal College of Psychiatrists, 2007)and ranges from ‘near-label’ prescribing to practicesthat have little foundation in evidence.

Benzodiazepine use is associated with risk of dependence, daytimesedation, cognitive impairment and falls (American Psychiatric Association, 1990).Although use of this class of drugs is discouraged in prescribingguidelines, it is common in real-world settings and is oftenresistant to change (Oude Voshaar et al, 2003; Caswell et al, 2006). It is interesting that reduction in use does not necessarilyequate with lower subsequent incidence of associated adverseevents such as falls (Wagner et al, 2007), emphasising thegap that can exist between clinical activities and presumed benefits in patient outcomes. In our population we noted agradual increase in use of zopiclone, in keeping with a perceptionof better tolerability and reduced dependency potential comparedwith benzodiazepines, but gathering evidence of misuse anddependence potential needs to be noted (Mahomed et al, 2002).Other work suggests low-dose antipsychotics as a relatively benign substitute for benzodiazepines (Hamann et al, 2003), but emerging evidence of metabolic and cerebrovascular effectsis a cause for considerable concern (Lieberman, 2004; Schneider et al, 2005)and emphasises the need for careful monitoring where theseagents are used ‘off licence’.

Some aspects of prescribing are more difficult to reduce owingto factors such as patient reluctance (Oude Voshaar et al,2003; Raju & Meagher, 2005) as well as perceived clinicalbenefit. Some have justified long-term benzodiazepine treatmentfor patients with disabling and treatment-refractory anxietydisorders where benzodiazepine use is associated with enhancedquality of life (Williams & McBride, 1999), but the characteristicsof these patients remain unclear and evidence points to over-rather than under-utilisation in current practice. In the caseof anticholinergic use, current opinion (World Health Organization, 1990)suggests that approximately 5% of patients receiving typical antipsychotic treatment require maintenance anticholinergictreatment. Consequently, a low level of use is consistent withoptimal management of extrapyramidal symptoms. It remains unclearto what extent further reduction in these practices is consistentwith optimal outcomes for patients. The need for evidence linkinggreater guideline adherence with improved patient outcomesis highlighted by Simpson et al (2005), who linked strict enforcementof National Institute for Health and Clinical Excellence (NICE) guidelines around cholinesterase inhibitor use to poorer patientoutcomes. Other work (e.g. Mortimer et al, 2005), using similarparameters of sub-optimal prescribing to those used in ourstudy, has linked greater side-effect burden to less-optimal prescribing that reduced as these practices diminished.

Ultimately a balanced approach to managing prescribing is required. Although some practices are clearly undesirable, others areacceptable for a minority of patients. The desire for greaterevidence-based practice needs to recognise the limited capacityof available knowledge to guide many aspects of treatment (especiallyaugmentation and combination therapy) as well as respectingthe autonomy and judgement of clinicians and patients in identifyingoptimal individualised therapeutic plans. As a basic principle, where prescribing deviates from suggested norms, this shouldreflect targeted pharmacological management, the benefits ofwhich are carefully monitored over time.

References

TOP