Identifying chronic illness using prescribing data

Children were defined as having diabetes in a given school census year if they cashed at least one prescription for insulin during the calendar year containing their school census date (yellow highlight in Table 14). Diabetes diagnoses were prospectively applied to all census years following a pupil’s first insulin prescription in the period 2009-2013.

Children who were not issued with a prescription for insulin across any of the census years but who were prescribed metformin or ‘other’ drugs from BNF section 6.1.2 in at least one census year were excluded from the analyses comparing children receiving diabetes

medication against children not receiving diabetes medication.

Table 14 Prescriptions used to define diabetes

BNF section Category Drug

6.1.1 Insulin Insulin Aspart

Insulin Detemir Insulin Glargine

Biphasic Isophane Insulin Biphasic Insulin Aspart Insulin Lispro

Soluble Insulin (Neutral Insulin) Isophane Insulin

Biphasic Insulin Lispro Insulin Glulisine

6.1.2 Metformin Metformin Hydrochloride

6.1.2 Other not commonly used Pioglitazone And Metformin Hydrochloride Vildagliptin And Metformin Hydrochloride Gliclazide Liraglutide Glibenclamide Exenatide Sitagliptin Pioglitazone Glimepiride Dapagliflozin Repaglinide Lixisenatide Glipizide Saxagliptin Linagliptin Tolbutamide 1

4.3.2.2.2 Asthma

Children were defined as having asthma in a given census year if they cashed either

1. More than one prescription during the calendar year containing their school census date for an inhaled steroid prescribed with either an inhaled long acting or short acting beta agonist (yellow highlight in Table 15)

2. More than one prescription during the calendar year containing their school census date for an inhaled steroid (green highlight in Table 15) and more than one

prescription during the same calendar year for either an inhaled long acting or short acting beta agonist (blue highlight in Table 15)

Asthma diagnoses were prospectively applied to all census years following the first year in the period 2009-2013 where conditions 1 or 2 above were met. Children who were issued with one or fewer prescriptions in 1 or 2 above in a given school census year or who received only leukotriene receptor antagonists (LTRA) or drugs within the ‘other not commonly used’ category in Table 15 were not defined as having asthma in that year. Children who did not satisfy conditions 1 or 2 in any of the census years but who were prescribed LTRAs or ‘other not commonly used’ drugs in at least one census year were excluded from the analyses comparing children receiving asthma medication against children not receiving asthma medication.

Table 15 Prescriptions used to define asthma

BNF section Category Drug

3.1 Bronchodilators Short acting beta agonist Salbutamol Terbutaline Sulfate

Salbutamol With Ipratropium Fenoterol Hydrobromide

Long acting beta agonist Salmeterol

Formoterol Fumarate Bambuterol Hydrochloride Indacaterol

3.2 Corticosteroids Steroid Beclometasone Dipropionate

Fluticasone Propionate Ciclesonide

Mometasone Furoate Budesonide

Steroid with long acting beta agonist Budesonide With Formoterol Fumarate Beclometasone Dipropionate And Formoterol Fluticasone Propionate And Formoterol Fluticasone Furoate And Vilanterol Salmeterol With Fluticasone Propionate 3.3 Leukotriene receptor antagonist (LTRA) Montelukast

Zafirlukast

3.1 - 3.3 Other not commonly used Theophylline1

Ipratropium Bromide1 Tiotropium2 Orciprenaline Sulfate2 Ephedrine Hydrochloride2 Aminophylline2 Aclidinium Bromide3 Glycopyrronium Bromide3 Sodium Cromoglicate4 Nedocromil Sodium4 1

received medications included in the definition of asthma are highlighted in blue, green and yellow

2

from section 3.1 but not commonly used so classed as other

3

from section 3.2 although not a corticosteroid

4

4.3.2.2.3 Epilepsy

Children were defined as having epilepsy in a given census year if they cashed at least one prescription from BNF section 4.8 during the calendar year containing their school census date (yellow highlight in Table 16). Epilepsy diagnoses were prospectively applied to all census years following a pupil’s first prescription from BNF section 4.8 in the period 2009-2013. No pupils were excluded from the analyses comparing children receiving epilepsy medication against children not receiving epilepsy medication.

Table 16 Prescriptions used to define epilepsy

BNF section Category Drug

4.8 All Sodium Valproate

Lamotrigine Carbamazepine Levetiracetam Topiramate Gabapentin Clobazam Pregabalin Clonazepam Ethosuximide Phenytoin Oxcarbazepine Lacosamide Midazolam Hydrochloride Zonisamide Phenobarbital Rufinamide Vigabatrin Perampanel Primidone Stiripentol Eslicarbazepine Retigabine Tiagabine 1

4.3.2.2.4 Attention deficit hyperactivity disorder

Children were defined as having ADHD in a given census year if they cashed at least one prescription from BNF section 4.4 during the calendar year containing their school census date (yellow highlight in Table 17). ADHD diagnoses were prospectively and

retrospectively applied to all census years in the period 2009-2013 if a pupil received at least one prescription from BNF section 4.4 in any census year. No pupils were excluded from the analyses comparing children receiving ADHD medication against children not receiving ADHD medication.

Table 17 Prescriptions used to define attention deficit hyperactivity disorder

4.3.2.2.5 Depression

Children were defined as having depression in a given census year if they cashed at least one relevant prescription during the calendar year containing their school census date: a tricyclic antidepressant from BNF section 4.3.1; a selective serotonin reuptake inhibitor (SSRI) from BNF section 4.3.3; one of the serotonin norepinephrine reuptake inhibitors (SNRI) commonly classed alongside SSRIs namely mirtazapine or venlafaxine from BNF section 4.3.4 (yellow highlight in Table 18). Depression diagnoses were applied

prospectively and retrospectively to all census years in the period 2009-2013 if a pupil satisfied the definition for depression in any census year. Children who did not satisfy the definition above across any of the census years but who were prescribed alternative medications from BNF sections 4.3.2 or 4.3.4 in at least one census year were excluded from the analyses comparing children receiving medication for depression against children not receiving medication for depression.

BNF section Category Drug

4.4 Atomoxetine Atomoxetine

4.4 Stimulant Methylphenidate Hydrochloride

Dexamfetamine Sulfate Lisdexamfetamine Dimesylate

1

Table 18 Prescriptions used to define depression