UKURAN DAMPAK DALAM EPIDEMIOLOGI Nurul Wandasari Singgih Prodi Kesehatan Masyarakat Univ Esa Unggul 2012/2013

Measures of Public Health Impact • Attributable Risk (AR) Number • Attributable Risk Percent (AR%) Percentage • Population Attributable Risk (PAR) Number • Population Attributable Risk Percent (PAR%) Percentage

Measures of Public Health Impact IMPORTANT! They all assume (require) that a cause-effect relationship exists between the exposure and the outcome.

Relative Risk vs. Attributable Risk Relative Risk: Measure of the strength of association, and indicator used to assess the possibility of a causal relationship. Attributable Risk: Measure of the potential for prevention of disease if the exposure could be eliminated (assuming a causal relationship).

Relative Risk vs. Attributable Risk • Etiology Attributable Risk: • Policy decisions • Funding decisions (e.g. prevention programs)

Tipe ukuran yang digunakan dalam epidemiologi Ukuran efek/dampak Merefleksikan dampak suatu faktor pada frekuensi atau risiko dari suatu masalah (outcome) kesehatan Merefleksikan kelebihan jumlah kasus karena suatu faktor (attributable) atau jumlah kasus yang dapat dicegah oleh eksposur (pemajan)

Ukuran-ukuran dampak Ukuran perbedaan dampak/efek Perbedaan risiko = Risk Difference (RD) = Attributable Risk (AR) = Excess Risk (ER) = Absolute Risk (AR) [Risiko pada kelompok terpajan] – [Risiko pada kelompok tidak terpajan] Berguna untuk mengukur besarnya masalah kesehatan masyarakat yang disebabkan oleh suatu pemajan bermanfaat untuk penilaian prioritas untuk aksi kesehatan masyarakat (Public Health Action)

Attributable Risk (AR) Among the EXPOSED: How much of the disease that occurs can be attributed to a certain exposure? AR AR% This is of primary interest to the practicing clinician.

Attributable Risk (AR) AR = Iexposed – Inonexposed = “Risk Difference” Develop CHD ISM = 84 / 3000 = 0.028 = 28.0 / 1000 INS = 87 / 5000 = 0.0174 = 17.4 / 1000 (background risk) Smoke Yes No 84 2916 3000 87 4913 5000 AR = (28.0 – 17.4) / 1000 = 10.6 / 1000

Attributable Risk (AR) Among SMOKERS, 10.6 of the 28/1000 incident cases of CHD are attributed to the fact that these people smoke … Among SMOKERS, 10.6 of the 28/1000 incident cases of CHD that occur could be prevented if smoking were eliminated.

Ukuran-ukuran dampak Ukuran perbedaan dampak/efek Perbedaan insidens kumulatif = Cumulative Incidence Difference= CID [IK pada kelompok terpajan] - [IK pada kelompok tidak terpajan] IK = Insidens Kumulatif

Ukuran-ukuran dampak Ukuran perbedaan efek Perbedaan rate/ perbedaan densitas insidens (IDD = Insidence Density Difference) IDD = [Densitas insidens dalam kelompok terpajan] - [Densitas insidens pada kelompok tidak terpajan]

Ukuran-ukuran dampak Ukuran perbedaan efek Perbedaan prevalens (PD = Prevalence Differrence) PD = [Prevalens dalam kelompok terpajan] - [Prevalens dalam kelompok tidak terpajan]

Attributable Risk Iexposed - Iunexposed

Ukuran-ukuran dampak/efek Ukuran perbedaan efek Attributable Risk (AR) Percent = AR%

Attributable Risk Percent (AR%) AR% = (Iexposed – Inonexposed) / Iexposed = “Etiologic fraction” Develop CHD ISM = 84 / 3000 = 0.028 = 28.0 / 1000 INS = 87 / 5000 = 0.0174 = 17.4 / 1000 (background risk) Smoke Yes No 84 2916 3000 87 4913 5000 AR% = (28.0 – 17.4) / 28.0 = 37.9%

Attributable Risk Percent (AR%) Among SMOKERS, 38% of the morbidity from CHD may be attributed to smoking… Among SMOKERS, 38% of the morbidity from CHD could be prevented if smoking were eliminated.

Attributable Risk Percent Iexposed – Iunexposed RR - 1 ------------------------------- = ------------ x 100% Iexposed RR

Ukuran-ukuran dampak Population Attributable Risk (PAR) = Attributable Fraction (population) atau Etiologic Fraction (population) = Population Attributable Risk Proportion = Population Attributable Risk Fraction Proporsi (atau fraksi) rate penyakit pada seluruh populasi yang mewakili rate penyakit dalam kelompok terpajan Rumus PAR

Ukuran-ukuran dampak Population Attributable Risk Percent (PARP) attributable fraction (population) atau etiologic fraction (population) Berarti proporsi kasus baru yang dapat dicegah jika pada semua orang yang tidak terpajan Rumus PAR%

Population Attributable Risk Percent PAR% = (Itotal – Inonexposed) / Itotal IT = 1100 / 10000 = 0.11 = 110 / 1000 INE = 250 / 5500 = 0.0455 = 45.5 / 1000 (background risk) Diabetes Weight Yes No Obese 850 3650 4500 Slim 250 5250 5500 1100 8900 10000 PAR% = (110 – 45.5) / 110 = 58.6%

Population Attributable Risk Percent PAR% = (110 – 45.5) / 110 = 58.6% In Tampa, 59% of the cases of diabetes may be attributed to obesity in the population… In Tampa, 59% of the cases of diabetes could be prevented if Tampa residents lost sufficient weight.

Prevented Fraction (PF) If relative risk <1 Proportion of potential new cases which would have occurred if the exposure had been absent Proportion of potential cases prevented by the exposure

PF: Vaccine efficacy

Ringkasan ukuran

Ringkasan ukuran

Ringkasan ukuran

Ukuran frekuensi penyakit

Ukuran frekuensi penyakit

Ukuran frekuensi penyakit RD = Risk Difference AR = Attributable Risk ER = Excess Risk PAR = Population Attributable Risk PF = Prevented Fraction