Perfil del migrante ecuatoriano retornado (OE 1.2.2.1)

Surveillance for an ocular disorder had not previously been undertaken through the BPSU. It was carried out, in this study, for three reasons: to enhance overall ascertainment o f cases, to allow level o f ascertainment to be estimated, and to minimise any possible under-representation of children with systemic diseases or multiple disabilities, or those in whom surgery was not undertaken for any reason.

3.1.3.1 Establishing surveillance for congenital and infantile cataract through the BPSU.

The methods used to establish and maintain this paediatric active surveillance system have been reported previously by the were not within the control o f this study. Surveillance for congenital and infantile cataract was undertaken following the formal application procedure, which included final approval o f the questionnaires to be sent to paediatricians to collect information on reported cases.

3.1.3.2 Case definition.

To avoid the possibility o f under-reporting of cases in whom the aetiology or onset o f cataract were unknown or unclear to the reporting paediatrician, a simplified and broader case definition was adopted for the paediatric surveillance scheme, and was approved by the BPSU.

Thus paediatricians were asked to notify

“any child in the UK, aged 15 years or less, with newly diagnosed cataract o f any severity and irrespective o f treatment undertaken!'

However, all communications about the study, including the study protocol distributed by the BPSU before the surveillance s ta r te d ,c la rifie d that congenital and infantile cataract was the disorder o f interest. Furthermore, the number o f children with acquired cataract seen by paediatricians was expected to be small.

3.1.3.3 Notification o f cases bv paediatricians.

The case ascertainment period for surveillance through the BPSU was concurrent with that o f the ophthalmic scheme, from October 1995 to September 1996 inclusive.

Notification cards were returned directly to the BPSU with respondents indicating the number o f new cases seen in the preceding month. As with all studies

facilitated by the BPSU, no identifying information was provided by the clinician on the notification card. Contact details o f clinicians notifying cases o f congenital and infantile cataract were forwarded by the BPSU to the study researcher who communicated with them directly to gather further information. The BPSU were responsible for reminding paediatricians with notification cards outstanding for three consecutive months.

3.1.3.4 Data collection.

Once a case was notified, the reporting paediatrician was sent a questionnaire to gather further information, accompanied by a covering letter explaining the purpose o f the study and identifying the principal investigator, who could be contacted to answer any queries about the study in general or the information sought.

Information was sought about detection, aetiology, clinical findings and initial management undertaken. (Appendix D, page 276) To ensure comparability o f data, the sections o f the questionnaire on detection and aetiology, including investigations and clinical assessments, were identical to those in the data

collection proformas used in the ophthalmic scheme. The section on management was modified for paediatricians as they may have had limited access to this information. Respondents were also invited to provide copies o f relevant

information in other forms, such as copies o f correspondence, investigation results or relevant sections o f the case notes, if they wished to. The same unique

identifiers (section 3.1.2.6, page 73) were sought from reporting paediatricians as from ophthalmologists to allow matching o f cases notified by both sources. A summary o f underlying or associated causes o f congenital and infantile cataract described previously (Table 2-5, page 40) was appended to the questionnaire, to help clinicians complete the section on aetiology. A reply-paid envelope was provided for return o f the questionnaire.

On receipt o f a completed questionnaire, a letter was sent to the reporting paediatrician to thank her/him for completing and returning it, and as confirmation that it had been received.

Up to three reminders, at eight weekly intervals, were sent to paediatricians from whom completed questionnaires about notified cases had not been received.

The study identification number allocated to each case report by the BPSU, using a sequential coding system combining year, month and number o f reports, was assigned to each questionnaire before it was sent. This ensured that any

completed questionnaires returned without the respondent’s name could be traced, to allow her/him to be thanked and to avoid reminders being sent inappropriately. The use o f a consistent identification number also facilitated the regular feedback undertaken to the BPSU about study progress.

Reporting paediatricians were also asked to identify, on the questionnaire, the ophthalmologist(s) involved in the management o f the case, with the

understanding that they would be contacted only if they were not already respondents in the ophthalmic scheme. Thus if a child was under the care o f an ophthalmologist who was not on the ophthalmic reporting base, she/he was contacted. A letter was sent outlining the study, inviting her/him to join the ophthalmic scheme and asking whether she/he would be willing to provide

information on the case notified by the paediatrician, irrespective o f whether she/he would be joining the reporting base. Data collection proformas were also sent with this initial correspondence. On receipt o f a completed proforma, a letter was sent to thank the ophthalmologist. A single reminder was sent to

ophthalmologists who did not reply to the initial letter.

3.1.3.5 Encouraging response.

A summary o f the surveillance study was published in the BPSU monthly bulletin before the start o f the case ascertainment period.’’* Subsequently, case

ascertainment was reported through this bulletin each month. A more detailed progress report was included in each annual report of the BPSU.'*^ The study was publicised through the newsletter o f the British Association for Community Child Health. In addition, as required, both written and verbal communications were made with reporting paediatricians throughout the case ascertainment period.

3 .2 Ev a l u a t i o n o ft h e s u r v e i l l a n c e s c h e m e s.

The surveillance schemes were evaluated to assess compliance o f clinicians with the notification system, specificity o f reporting and level o f ascertainment achieved.