1 / 95

DESAIN PENELITIAN

DESAIN PENELITIAN. Sumarni Faculty of Medicine & Public Health Tadulako University. Problem. Hipotesis. Prediksi. Uji. Bukan. Kesimpulan. Proses Ilmiah. HASIL PENELITIAN. Pertanyaan Penelitian Tujuan Hipotesis. Nilai sebenarnya. +. =. Kesalahan. HASIL. Kesalahan.

mcroft
Télécharger la présentation

DESAIN PENELITIAN

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. DESAIN PENELITIAN Sumarni Faculty of Medicine & Public Health Tadulako University

  2. Problem Hipotesis Prediksi Uji Bukan Kesimpulan Proses Ilmiah

  3. HASIL PENELITIAN Pertanyaan Penelitian Tujuan Hipotesis Nilai sebenarnya + = Kesalahan HASIL

  4. Kesalahan • Kesalahan sistematis/bias • Kesalahan acak • Kesalahan sistematis dihindari dengan penggunaan metodologi dan desain penelitian yang tepat • Kesalahan acak dihindari dengan penggunaanstatistik yang tepat

  5. KESEIMBANGAN ANTARA VALIDITAS & FISIBILITAS ? Desain Metodologi Statistik Fisibilitas Validitas Proposal penelitian

  6. Alam nyata Alam impian Problem Hipotesis Pembuktian Prediksi Hasil Analisis Data Interpretasi Kesimpulan Hipotesis yang baru

  7. DESAIN PENELITIAN Laboratorium Eksperimental Binatang Percobaan Perlakuan Manusia Deskriptif (Tidakada perbandingankelompok) Paparan alamiah Cross-sectional (Ada perbandingan kelompok) Observasional Cohort Analitik Case control Causal comparative correlational Metaanalisis

  8. O E Prospektif Cohort O E Alamiah Retrospektif O E Eksperimental Case-control Perlakuan Lampau Sekarang Y.a.d. DESAIN PENELITIAN MENURUT WAKTU Cross sectional

  9. Case-Control Study

  10. Onset of study Exposed Cases Unexposed Exposed Controls Unexposed Direction of inquiry Schematic diagram of case control study Time

  11. Odds & Odds Ratio (OR) Odds: probabilitasterjadinyasuatukeadaandibandingkandenganprobabilitastidakterjadi Odds ratio: • ukuranhubunganpaparandengankejadianpenyakit • untukmengetahuiseberapabesarresikosuatupaparansehinggamenyebabkanpenyakitdibandingkanbilatidakterkenapaparan

  12. Case control study Odds ratio = ad / bc Odds = prob of even/ 1- Prob of even

  13. Reye’s syndrome • Occurs in children 2-16 yrs as a serious complication of influenza B or less often – influenza A or varicella zoster infection. • It begins with 1-2 day of nausea and vomiting followed by CNS symptoms, including changes in mental status, that range from lethargy to coma and encompass delirium and seizure. Elevated serum transaminase level and elevated amonia concentration, and hepatomegaly are common

  14. Aspirin use during viral illness among children and subsequent risk of developing Reye’s Odds ratio = 28 x 25 / 35 x 2 = 10

  15. Interpretation of OR • The odds of having disease in question are OR times greater among those exposed the suspected risk factor • For rare disease ( e.g. chronic disease which have prevalence < 10%) OR approximates RR • That is, the risk of the disease is approximately OR times greater among those exposed to the suspected risk factor • RR = [P(D+/E+)] : [P(D+/E-)] = [a/(a+b)] : [c/(c+d)]. For rare disease a and c are small relative to b and d. Thus a/b approximates a/(a+b) and c/d approximates c/(c+d)

  16. Interpretation of OR….. cont • The larger the value of OR, the stronger the assoociation. • When the value of OR is close to 1, the disease and exposure to the risk factor are unrelated • Value of OR < 1 indicate a negative association

  17. OR and study design • Since P(D+/E+), P(D+/E-), P(D-/E+) and P(D-/E-) can be estimated from result of a cohort or an experimental study, OR can be calculated directly these study designs are employed

  18. OR in a case-control study • The conditional probability of disease P(D+/E+), P(D+/E-), P(D-/E+) and P(D-/E-) can not be calculated directly from the result of a case control study • Estimates of the conditional probability of exposure can be obtained in a case-control study.

  19. Oral Contraceptive Use & Breast Cancer • Problem: Is OC associated with the risk of breast cancer? • Research Hypothesis: There is an association between OC use and breast cancer • Cases: All women 20-54 years old with newly diagnosed breast cancer who reside in one of eight geographic regions in the United States. The women were identified through population-based tumor registries • Controls: Women of the same ages selected at random from the general population of the same region and the same period when cases were diagnosed

  20. Selection of Cases Usually based on outcome • Incident outcomes • Prevalent outcomes

  21. Selection of Controls Should be selected according to predetermined criteria to ensure the absence of outcome May be better to choose subject with similar referral, surveillance, and other factors capable of distorting the study sample

  22. Exposure The primary exposure of interest is prior exposure, not contemporaneous one Need biologic model for how exposure causes outcome • Dose, duration, and period of exposure should be specified ahead of time

  23. Case-Control Study Advantages • Statistically more efficient when outcome are rare • Quicker when outcome are delayed • Less costly Disadvantages • Enhanced potential for sample distortion • Exposure ascertainment more prone to error and bias

  24. COHORT STUDY

  25. Cohort Study • Cohort: a group of people that exposed to particular exposure in a period of time • Cohort study can be conducted prospectively or retrospectively

  26. Cohort study • Retrospective Cohort, both exposure and outcome observed have been occurred before study conducted • Prospective Cohort study, subject of the study may already been exposed or not yet been exposed when a study started, but the outcome not yet been available

  27. Disease Disease Exposed Exposed No disease No disease Disease Disease Unexposed Unexposed No disease No disease Retrospective and prospective cohort study Past Present Future

  28. Requirement • Exposure criteria is clear and specific • Intensity • Duration • Regularity • Variability • Duration of follow-up • Outcome measurement: blind, objective

  29. Time Onset of study Disease Exposed No disease Disease Unexposed No disease Direction of inquiry Schematic diagram of cohort study

  30. Cohort study Relative risk (risk ratio) = a/(a+b) : c/(c+d)

  31. Relationship between 10 minute Apgar scores and risk of death in the first year of life among children with birth weights of at least 2500 g Relative risk (risk ratio) = 42/(42+80) : 43/(43+302) = 2.8

  32. Interpretation of RR • The disease is RR times more likely to occur among to exposed to the suspected risk factor • The larger the value of RR, the stronger the association • The value of RR close to 1 indicate that the disease and exposure to the risk factor are unrelated • Value of RR < 1, indicate a negative association

  33. RR and study design • RR can be directly calculated only in a cohort or experimental study • Because incidence can not be estimated from a case control study, RR can not be calculated directly. Under some circummctances, the RR in a case control study can be estimated by OR

  34. a/b OR = a/(a+b) c/d RR = c/(c+d) Result of hypothetical cohort study

  35. Relative risk (RR) Risk of disease if exposed to risk factor = Odds that exposed individual will have disease Risk of disease if not exposed to risk factor Odds ration = Odds that non-exposed individual will have disease Strength of the association Odds of disease = P(disease)/1 – P (disease) = P (disease) / P (no disease)

  36. Pemilihan Subjek kasus dan kontrol • Keduanya diambil dari populasi yang sama • Keduanya belum menderita penyakit yang akan diteliti saat penelitian dimulai • Karakteristik sampel kasus dan sampel kontrol sama • Ada informasi yang ekual antara kedua grup • Kedua grup harus dapat dihubungi dan dapat di follow up

  37. Contoh beberapa penelitian

  38. CRP and BMI predict outcome in end-stage respiratory failure,Cano et al, 2004, Chest, 126: 540-546 • Menentukan faktor prognosis kematian dan kesakitan utk penyakit pernafasan stadium akhir • Penelitian Cohort (COPD: 42,8%, restrictive disorder 36,3%, campuran 13,5%, bronkiektasis 7,4%) • CRP, BMI, PaO2 dan kortikosteroid oral mrpk prediktor independen kemampuan hidup

  39. Graf failure < 0,5 g/hr: 13,3% 0,5-1 g/hr: 25,3% > 1 g/hr: 45,8%

  40. HR: 4,58 HR: 7,03

  41. Oscarson et al., menyimpulkan • Kenaikan kadar TnT pasca operasi memberi risiko 15 kali kematian pd th pertama • Pemeriksaan TnT untuk lansia (sering terjadi silent myocardial ischemia) pd masa perioperatif bermanfaat utk menilai risiko kematian pd tahun pertama pasca operasi

  42. Anti p53

More Related