SKRINING SAWITRI

V

AT RISK!! Populasi total Sakit Mencari pengobatan Rawat inap Meninggal POPULASI  perkembangan dari sehat menjadi sakit yang berbeda derajat beratnya Populasi total AT RISK!! Sakit Mencari pengobatan Rawat inap Meninggal

Dx dini penyakit di komunitas Comparing with GOLD STANDAR SKRINING UJI DIAGNOSTIK Program A study  accurate test Dx dini penyakit di komunitas Terapi Mencegah penularan Mencegah kecacatan Comparing with GOLD STANDAR

PENELITIAN SKRINING (UJI DIAGNOSTIK)

Skema Uji DIAGNOSTIK “Healthy Sample” Positive SCREENING TEST Negative SCREENING TEST Confirm Dx Confirm Dx Not sick TRUE NEGATIVE Sick, FALSE NEGATIVE Sick, TRUE POSITIVE Not Sick FALSE POSITIVE

AKURASI Spesifisitas Nilai Prediktif Likelihood Ratio 2. RELIABILITAS 1. VALIDITAS Sensitivitas Spesifisitas Nilai Prediktif Likelihood Ratio Persentase (%) 2. RELIABILITAS

Sensitivitas Kemampuan tes untuk menunjukkan secara benar orang-orang yang benar-benar sakit TP TP + FN Spesifisitas Kemampuan tes menunjukkan secara benar orang-orang yang benar-benar tidak sakit TN TN + FP

STANDAR BAKU JUMLAH POSITIVE TP + FP NEGATIVE (FN) (TN) FN + TN TOTAL DISEASE NO DISEASE JUMLAH POSITIVE TRUE POSITIVE (TP) FALSE POSITIVE (FP) TP + FP NEGATIVE FALSE NEGATIVE (FN) TRUE NEGATIVE (TN) FN + TN TOTAL TP + FN FP + TN N S K R I N G

NILAI PREDIKTIF 1. Positif 2. Negatif PV positif: Proporsi orang yang benar-benar sakit setelah mendapatkan hasil tes positif TP = TP + FP

PV Negatif Proporsi orang yang benar-benar tidak sakit setelah mendapatkan hasil tes negatif TN = TN + FN

Faktor-faktor yang mempengaruhi nilai prediktif Sensitivitas dan spesifisitas Prevalensi penyakit yang asimtomatis  semakin tinggi prevalensi penyakit, nilai prediktif positif akan semakin tinggi

TES DENGAN DATA KONTINYU (INTERVAL)

CUT OFF POINTS Tes dengan > 2 kategori hasil Contoh: Glaukoma Test Y: 1. TIO > 26 2. TIO 22 – 26 3. TIO < 22 Tes X : 1. GLAUCOMA 2. Tidak GL.

Lanjutan …..Cutoff points SENS? SENS? SPEC? SPEC? Healthy Sick 22 26 Intra Occular Pressure

MENINGKATKAN AKURASI SEQUENTIAL (2-STAGE) TESTING SIMULTANEOUS TESTING Melakukan tes tambahan pada hasil yang sudah positif Meningkatkan spesifisitas SIMULTANEOUS TESTING Melakukan dua tes secara bersamaan pada populasi Meningkatkan sensitivitas

RELIABILITAS Jika suatu tes Valid : pasti reliabel Kemampuan alat untuk menunjukkan hasil yang konsisten ketika digunakan lebih dari satu kali pada individu yang sama pada situasi yang sama Jika suatu tes Valid : pasti reliabel Reliabel : tidak selalu valid Tidak reliabel : pasti tidak valid

Tes Urine: Px 1 (-) Px 2 (+) Px 3 (+) Px 4 (-) Tes Urine: Px 1 (-) Contoh : Roni dengan hasil BSN/GTT (standar) telah didiagnosis diabetes Tes Urine: Px 1 (-) Px 2 (+) Px 3 (+) Px 4 (-) TIDAK RELIABEL Tes Urine: Px 1 (-) Px 2 (-) Px 3 (-) Px 4 (-) RELIABEL TAPI TIDAK VALID

Faktor-faktor: Variasi tes Variasi pengamat Stabilitas reagen Fluktuasi sample atau spesimen Variasi pengamat Inter observer Intra observer

PROGRAM SKRINING

Population-based screening is where a test is offered systematically to all individuals in the defined target group within a framework of agreed policy, protocols, quality management, monitoring and evaluation. Opportunistic case-finding occurs when a test is offered to an individual without symptoms of the disease when they present to a health care practitioner for reasons unrelated to that disease

WHO PRINCIPLES OF EARLY DISEASE DETECTION Condition • The condition should be an important health problem. • There should be a recognisable latent or early symptomatic stage. • The natural history of the condition, including development from latent to declared disease should be adequately understood. Test • There should be a suitable test or examination. • The test should be acceptable to the population. Treatment • There should be an accepted treatment for patients with recognised disease. Screening Program • There should be an agreed policy on whom to treat as patients. • Facilities for diagnosis and treatment should be available. • The cost of case-findings (including diagnosis and treatment of patients diagnosed) should be economically balanced in relation to possible expenditure on medical care as a whole. • Case-findings should be a continuing process and not a ‘once and for all’ project.

Skema PROGRAM SKRINING “Penduduk sehat” Positif Negatif Tes Skrining Konfirmasi Dx “SEHAT” Sakit, TRUE POSITIVE Tidak sakit FALSE POSITIVE

CRITERIA TEST TO BE MET is highly sensitive and is highly specific. is validated and safe. has a relatively high positive predictive value and has a relatively high negative predictive value. is acceptable to the target population including important sub groups such as target participants who are from culturally and linguistically diverse backgrounds, people from disadvantaged groups, and people with a disability. There are established criteria for what constitutes positive and negative test results, where a positive test result means that the person needs further investigations, and a negative test result means the person is rescreened at the usual interval, where applicable.

TES MANA YANG HARUS DIPILIH? SENSITIVITAS DAN SPESIFISITAS SUMBER DAYA YANG TERSEDIA DAMPAK

TES MANA TIDAK TERBUKTI EFEKTIF? http://www.racgp.org.au/redbook/15

PROGRAM SKRINING SEDERHANA Skrining depresi usila  GDS 15 Obesitas  IMT ????