Clinic assessment for methylphenidate maintenance therapy in secondary care: are parental questionnaires useful?

AIMS AND METHOD

There is poorer control of hyperactivity symptoms in communityclinics than research settings, and difficulty in detectingsuch symptoms without standardised measures. Hyperkinetic children(n=29) were evaluated at follow-up using the parental versionof the Strengths and Difficulties Questionnaire (SDQ) and,independently, routine clinic reports to test the value ofa parental questionnaire.

RESULTS

The parental SDQ identified symptoms in more patients (25, 86%v. 13, 45%), but high levels of symptoms did not necessarilyimply impairment. Even clinically identified hyperactivityprovoked no change in treatment.

CLINICAL IMPLICATIONS

Parental questionnaires alone are unlikely to improve clinicpractice. Research is needed into what factors influence clinicaldecisions regarding treatment maintenance for hyperkinesis,and the adaptation of structured protocols from major researchtrials should be considered.

Introduction

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Introduction

Hyperactivity is the most common neuropsychiatric disorder ofchildhood, with prevalence rates for the broader syndrome -attention-deficit hyperactivity disorder (ADHD) - of between2 and 18% (Rowland et al, 2002) and around 1% for the narrowersyndrome of hyperkinesis (Meltzer et al, 2003). Effectivetreatments are available, but routine community treatment ofthe disorder is less effective than similar treatments delivered in research protocols (MTA Cooperative Group, 1999). Althoughthere could be several reasons for this, one possibility thathas not received attention is that community services mightstruggle to detect persistent hyperactivity symptoms. It isknown that hyperactivity symptoms may be underestimated withoutthe use of screening questionnaires at initial assessment (Foreman et al, 2001), judgements of symptom severity may not relate to diagnosticcriteria (Evink et al, 2000) and prescription of stimulantsmay be better predicted by oppositional/defiant behaviour thanhyperactivity itself (Angold et al, 2000). Current guidelinesrecommend using multiple informants and standardised measuresfor diagnosis (National Institute for Clinical Excellence, 2000)but there are no recommendations for follow-up assessments,which typically involve a single clinician interviewing the parent and assessing the child in clinic. We therefore comparedclinical judgements of continuing hyperactivity with a standardisedparental questionnaire on a sample of hyperkinetic childrenattending a routine community stimulant follow-up clinic. Wewished to see whether the clinical use of a standardised measurewould be a helpful addition to the routine assessments cliniciansalready made in follow-up clinics.

Method

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Method

Design, service and sample
The study was designed to audit follow-up assessments of childrenwith a diagnosis of hyperactivity attending a secondary carechild and adolescent mental health service (CAMHS), servinga population of approximately 90 000, who were prescribed methylphenidatein either conventional or slow-release forms. Questionnaireand routine clinic assessment of continuing hyperactivity werecompared. The service diagnosed ICD–10 hyperkinesis (World Health Organization, 1992),rather than ADHD (Taylor et al, 1998) and was provided bytwo psychiatrists (D.M.F. and R.K.). The audit standards setwere that no child reviewed should have significant hyperactivityon either clinic report or the Strengths and Difficulties Questionnaire(SDQ; Goodman, 1999), and there should be no difference betweenpatients of the two psychiatrists. Follow-up assessment wasbased largely on interview and examination of the parents and child at clinic attendance, with the parents being treatedas the main informants about all unobserved aspects of thechild’s life. School and other reports or questionnaireswere sought only if the clinic assessment or parental accountswere unclear. Figure 1 summarises the exclusion criteria andstudy attrition.

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Fig. 1. Selection criteria and attrition path. Questionnaires were sent by post with one follow-up telephone call. SDQ, Strengths and Difficulties Questionnaire.

Measures
Parents were sent the extended version of the parental SDQ (Goodman, 1999),which is now freely available in several languages (http:/www.sdqinfo.com). We used the UK version for 4- to 16-year-olds, which coveredthe clinic’s typical age-range. This is a brief screeningquestionnaire of 25 symptom and 8 impact questions with check-boxresponses, which provides scale measures for general caseness(total difficulty score), prosocial behaviour, peer relationships,hyperactivity, conduct and emotional problems. Diagnostic algorithmscombine symptom and impact scores to provide population-basedcut-offs for predictions of three broad diagnostic categories:conduct–oppositional disorder; anxiety–depressive disorder; and hyperactivity–inattention disorder (Goodman et al, 2000). These predictions are rated as ‘unlikely’, ‘possible’ (the top 10-20% of the population) or ‘probable’(the top 10% of the population) for each diagnosis (Goodman, 2001).

The routine clinical assessment was always summarised in a letterto the referrer that included physical status (weight, heightand body mass index), psychiatric symptoms, recommended medicationdosage or changes, and change in any psychosocial treatmentoffered. The letters closest in time prior to (and thus independentof) the SDQ were coded by D.F., who was unaware of the SDQ scores,into hyperactive symptoms being ‘unlikely’, ‘possible’or ‘probable’, thus generating an ordered categoryset equivalent to that of the SDQ but reflecting clinical opinion. Mention of overactivity, impulsivity and inattention in theletter was coded as ‘probable’; at least one ofthese symptoms as ‘possible’; and no mention ofany hyperactive symptom was coded as ‘unlikely’.Other information abstracted from the case records is shownin Table 1.

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Table 1. Sample characteristics

Analysis
Owing to the small size of the data-set, tabulation and visualdisplays were used to display important relationships, withnon-parametric tests for hypothesis testing.

Results

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Results

The questionnaire was sent to 50 families but returned by only29 (58%); the response probably reflects data collection havingto be undertaken during the school summer holidays, which alsoprevented the concurrent use of the teachers’ versionof the SDQ. No difference was found between returners and non-returnerson clinic estimate of hyperactivity (Jonckheere–Terpstratest 172, P=0.23).

The sample characteristics are summarised in Table 1; 15 ofthe children (52%) were seen by D.F., 14 (48%) by R.K. Therewas no difference between the children for either the clinical(Mann–Whitney U=79, P=0.27) or the SDQ (Mann–WhitneyU=86.5, P=0.43) estimates of the probability of the childrenstill being significantly hyperactive. So, this audit standardwas met.

The audit standard that no child should have significant continuing hyperactivity was not met using either criterion, and the overallagreement between them, although significant, was poor (Table 2):25 (86%) children were symptomatic by the SDQ, 13 (45%) byclinical opinion. No other variable predicted the clinicians’estimate of symptoms. No child had their medication or psychosocialtreatment changed at the clinic appointment referred to inthe letter.

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Table 2. Association between questionnaire and clinic assessments of continuing hyperactivity¹

Fifteen children (52%) had a maximum score on the SDQ hyperactivity sub-scale. Although numerical analysis suggested an overallassociation between the SDQ measure of impairment–impactand this sub-scale (Spearman’s rho=0.436, P=0.009), Fig. 2shows that this relationship broke down at higher hyperactivitysub-scale scores, as did the relationship between the hyperactivitysub-scale, the SDQ total difficulty score and clinical opinion.

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Fig. 2. Hyperactivity v. impairment scores on the Strengths and Difficulties Questionnaire (SDQ). Clinical opinion of presence of continuing hyperactivity: ${circ}$ , unlikely; ${square}$ , possible; X, probable.

Discussion

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Discussion

A substantial proportion of young people attending an ordinary hyperactivity medication follow-up clinic have continuing problemswith hyperactivity, despite having been in treatment for, onaverage, more than 3 years. The SDQ detected more hyperactivesymptoms than the clinic letters indicated. However, high SDQscores for hyperactive symptoms had little association withSDQ estimates of total difficulty or impairment. So, although parental SDQ can demonstrate imperfections in the detectionof hyperactive symptoms in ordinary clinic assessment, itsroutine adjunctive use could further confuse, rather than improve,assessment at follow-up, as the differing scores do not afforda simple interpretation. Although a range of physical and psychologicaltreatments are used (Table 1) no child’s treatment waschanged, despite continuing hyperactive symptoms being identifiedclinically in nearly half. Clinicians may be considering therisk of side-effects, or they may be benchmarking current symptomsand impairment against greater past difficulty, neither ofwhich this study measured.

The chief limitations of the study are the small sample size,the risk of selection bias, and the children being from a single,secondary care psychiatric clinic. Despite all this, includingthe inevitable confounding of general with local characteristicsof staff and patients, the sample characteristics, symptomsand treatment profiles are typical of hyperactive childrenseen and treated in secondary care (Coffey, 1997; Swanson et al, 2001). The study did not include children with non-hyperkinetic ADHDor children managed in primary care alone. It is likely thathyperactivity will be harder to detect in the broader syndromeof ADHD, and that more general services will have less skilland experience than dedicated secondary care provision, so the difficulties identified here may be more apparent in settingsusing the broader diagnosis and fewer specialist staff. Thestudy did not separately consider other factors affecting treatmentdecisions, such as perceived risks of side-effects, parentalpreferences over drug dosage or current availability of psychologicaltreatments, so it cannot be inferred that the clinicians’decisions not to modify treatment in the presence of hyperactivesymptoms are irrational.

As was suspected, even alert clinicians do struggle to detectcontinuing hyperactivity in follow-up clinics. The SDQ resultssuggest that simply adding a questionnaire to be completedby parents at follow-up will identify more symptoms, but itsclinical significance will be uncertain. Given the small samplesize and the single centre of the present study, larger confirmatory studies in multiple centres are needed. It seems unlikely thatanother questionnaire would have produced different results:most questionnaires seem similar in their abilities to detecthyperactivity (Collett et al, 2003), and there seems littleto choose between more general and more specific questionnaires(Foreman et al 2001). It might seem prudent to ensure thatfollow-up assessment includes additional data to those providedby the parents and clinic observation (e.g. first-hand reportsor observations from the school). However, following such recommendationswould require limiting follow-up clinics to the school terms,and making prior arrangements to obtain school-based reportsor questionnaires. Both these changes would present considerablelogistical problems and might not change clinicians’ behaviour,as even the clinical identification of continuing hyperactive symptoms does not necessarily lead to a change in treatment.Further research is needed to clarify the factors influencingclinicians’ treatment decisions: for example, clinicaldetection of side-effects and impairment was not assessed inthis study. Structured treatment protocols that limit clinical judgement, as used in research trials, might produce betteroutcomes. This goes beyond current clinical guidelines (American Academy of Pediatrics, 2001;National Institute for Clinical Excellence, 2000) but is consistentwith research. However, it would need testing by appropriatestudies.

References

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